Hey Mr Joey sorry to ask but i have a 03 pathfinder that i completely rebuilt the vq35de in it last year down to regrind and cylinder hone. compression is 185-195 between all cylinder after rebuild. Was having a intermittent hard start last week that was fixed with a fuel pressure reg and dampner along with a new fuel pump. my LTFT are right at -5.5 on both banks. shouldnt they be closer to 0 - +/-1?
Great video. I had this same diagnosis based off the pids. Fuel trims with readings alone with both banks were a clear indication. Reading active O2 would have also pointed that direction. Could have also looked for a lack of fuel but considering least intrusive diagnostics first the Vac leak is the most likely culprit with the easiest tests to verify.
I realise the video is old and that competition is finished long time ago but i'd like to verify my answer. Answer: A stuck open EGR will throw a lean code because a stuck open EGR is basically a huge vacuum leak, letting massive amounts of unmetered air going into the engine which will obviously be detected by 02 causing the ECU to call for more fuel. Thank you for your time
Hey Rok, thanks for trying at the question anyway. I respond with a question...is an EGR being stuck open a vacuum leak? How much oxygen is in EGR gas? ;) Mike Becker, Senior Technical Instructor
Hello, just to (try)answer your questions. EGR sits between exhaust and intake manifold, right? Therefore, a stuck open EGR will create a vacuum leak by allowing the air from intake to escape, at least partially. As for the second question, there would be none or very little, and i know that you've mentioned that in the video.
I have a 02 f150 4.2 with a bank 1&2 sensor one both sides. I have done an intake job reseal. Also did a timing cover replacement and replace synchronizer . Also changed MAF because of damage to the MAF
Great video. Do you know what ECU does in the presence of one P017... code? It will run a programmed map or will continue to use o2 sensors and others? What i understood it is that when P017... occurs the ECU knows that a problem exist but can not identify the cause. I hope i am right. Thank you.
Ms Marie from South Main Auto recommended. Very good...even for those of us who are just hobbyists rather than professionals. Beautifully explained. Very helpful.
Tech B is correct due to the valve stuck open in this instance its letting more fumes pass than being calculated and it is acting like a vacuum leak and is a continuous flow of gasses.
Hahaha love the "don't think that's measured in ugga duggas" comment! Great videos guys, I'm a DIY'er but I've learned more about closed loop fuel systems and related sensors in your last couple of videos than I ever thought was necessary - but now it's clear that it is.
What do you check if the BARO is not correct? Hyundai Tucson we were looking at had P0171 & P0174 and no vac leaks and BARO was showing 23inHg with KOEO and with vehicle running (local BARO 30inHg)...no change when unplugging the IAT or MAF sensor...could not located a specific BARO sensor on the vehicle and ALL-Data did not show a sensor location (i believe it is integrated into the MAF). 2008 Hyundai Tucson 2.7L. The PCM was adding as much as 25-31.8% on both Banks...sometimes was throwing a P0170 & P0173 code also.
I actually can't remember if I was monitoring the BARO PID when I unplugged the MAF. I should also add that vehicle seem to run worse with MAF unplugged, and no noticeable change in running condition w/ IAT unplugged. All 4 O2 sensors seemed to be working correctly from the live data but sometimes seemed slow to respond. No O2 sensor codes tho, and that may have been my tablet just running slow on updating the live data which it seems to do if I am graphing 4 PIDS at once. All 4 oxygen sensors showed close to 450mV w/ KOEO. They were usually like ~410-430mV actually. When you fire it up, the upstreams do start switching when it enters CL but the downstreams go hard lean then the STFT go hard positive +31% then as the LTFT pick up the slack the STFT drop to +10-15% ish. Everything in my experience was pointing towards vacuum leak but we checked with spraying carb cleaner w/ engine running near potential vac leak areas as well as testing for vac leaks w/ a smoke machine...neither way found any leaks. I thought maybe low fuel pressure, because it something affecting both banks. Unfortunately my scan tool wont pull fuel rail pressure data and the vehicle does not appear to have a typical schrader style valve to test the pressure directly. After one of the many times of clearing and resetting everything during 2 days of testing it just didn't do it, it didn't pull any codes, the fuel trims all seemed good. And no CEL, i was shocked... So i went and test drove it and the readiness monitors were checking off one by one and I thought, IDK this thing might have just fixed itself. I only needed 1 more readiness monitor to get it to pass SI (you can have 1 not ready, it had 2) and before either of them popped to ready....dayum MIL came back on and pulled System too lean bank 1 & 2 again. This one is really giving me trouble, if anyone can help.
I checked and found a TSB about the air intake box sometimes being an issue, followed TSB instructions and verified it was not our problem...we did other testing too that I am sure I can't remember right now...but any input from anyone would really be appreciated. I am at a total loss here.
There is never any detailed fuel trim videos on rich trim. I've replaced IAT, 02's, CT, MAF, MAP, N80 purge valve, i've tested for vacuum leaks, checked the FPR Cannot get rid of the rich fuel trim.
Rich conditions are less common than lean but can be diagnosed the same way. Force the engine lean, do the trims and 02's react accordingly? How's fuel pressure after the key is shut off? Maybe a leaky injector? Mike Becker, Senior Technical Instructor
Hello Mike, Remove air intake manifold, discovered piston #1-, its air port, had carbon build-up in gobbles. Replaced the gasket torque it to 13.666 inch lbs, checked fuel trims: long term was higher 10 mv idling, on acceleration it when up to 39.45 mv. short term, was -8 to -15 idling, on acceleration it dropped to zero and to .5 mv I re-torqued the manifold while hot, the long term is now stable at 2.3 mv short term between -5 to -14 while idling. accelerating while driving the shorterm is stable between 2.3 to .5 mv short term moved to positive 5. deceleration drops to 00 to -.1 to -.5 to -.10 it stays on the ten. removed spark plugs very clean no fouling, replaced with new sparks. injectors replaced too. checked with stethoscope all injectors sound good crispy and tight. the spark plug sound chirpy good frequency. however the piston chamber # 1 sound like weak oil rings, other piston sound clean and clear. Could the short term trims stable at -10; long term stable at 2.3 is this a sign of low compression? Oil was changed added 3.75 quarts after driving for one hour the next day checked oil it lost .25 oz it could be burning oil yet no signs of it coming out of exhaust pipe. checked vaccum with pump its at 22lbs perfect. check engine light is still on, I did not remove battery cable while working on it. Should I remove battery cable wait 3 minutes and re-connect it to see if the check engine light disappears? The on board computer tester still brings up code P0171. There was a pending code P0125 throttle position senor, thats because i did not tighten the bracket to ground enough it gone now after tightening its bracket to engine block.
Thank for the video. Could you help me make sense of these STFT and LTFT values. I have 07 ford taurus, for bank 1 STFT stays between +/-3%, but LTFT stays constant at about -12% at Idle. Bank 2 is lean at idle with +12% total fuel trim. When I increase RPM to 2500, STFT jumps between +/-6% and LTFT stays constant at -19%. Bank 2 improves at 2500 RPM with about +6% total fuel trim. OBD says cylinder 1,2, and 6 misfire. I have tested injectors, replaced the leaking injector already. What do these trim value mean? How come bank 1 is rich and bank 2 is lean? Thank you.
Does the engine have any other trouble codes? Something is causing the engine to run lean on one and rich on the other bank. Has the timing chain ever been off? Mike Becker, Senior Technical Instructor
@@GoTechTraining Thanks for the response. Currently, I only get 1,2,6 cylinder misfire codes when I erase the codes. In October 2019, after I reset ECM by disconnecting battery terminal, I did get P0420 and P0430 pending codes saying "catalyst system efficiency below thresold for both banks". I checked freeze frame data screenshots I took that time. LTFT on bank 1 was -14.1, and +3.1 on bank 2. STFT 1 was -1.6 and STFT2 was +1.6. From research, the rich condition on bank1 and lean condition on bank 2 eliminates some possibilities like vaccum leak, bad MAF, leaking egr valve, ECT sensor, fuel pressure regulator. there might be vaccum leak on just bank 2 but I am not sure how that could be possible since both banks are fed same way. So for rich condition, the remaining culprits are: 1) bad O2 sensor O2S1B1 (which seems to be working since it jumps between 0.1-0.85V) 2) Spark plugs on bith banks (I replaced spark plugs in December last year, so I am not sure if its bad, I am planning to check them tomorrow). 3) leaking fuel injectors (less likely because, when I saw cylinder 1,2 misfire last time I swapped them with cylinder 4,5, now there is still cylinder 1,2 misfire) 4) Catalytic converter (not sure since there is no rotten egg smell, just exhaust fume out of tail pipe) 5) Exhaust leak (I smell exhaust fume in cabin whenever I start AC or heater, I think there is exhaust leak. I have to check both banks exhaust system for leak, but not sure whether it should cause rich or lean condition) Do you think the exhaust leak is due to plugged catalytic converter? Do you think its the main culprit? Please let me know if I am checking things right way. Thank you very much
The EGR stuck open would cause a lean code because the air entering the intake manifold would be unmetered... not being metered by the mass airflow sensor would throw off the fuel trim to lean... letting in more air than fuel...
Thanks a lot for your videos and sharing your knowledge. I have a fault that both banks mixture are too rich. I checked the long term fuel trim (LTFT) using a cheap code reader, I found that on high way the LTFT is between 0 and -5%. When it's on idle or when I remove my feet on the accelerator pedal, it becomes really rich -20 to -25%. I bought a used MAF from the scrap and installed it but the problem persists. From your experience what can be the problem? Both banks have the problem, so I would rule out the injector leaking or spark plugs. I have a C250 4 matic V6 2012 gasoline. Thanks a lot
Hey 80goal, i'd be curious as to what the fuel pressure sensor reads. Maybe that reading is skewed and the fuel pressure is too high? Nothing is really common to that engine. Wish I had more to go off of for you. Mike Becker, Senior Technical Instructor
Guys, Thank You. It is awesome being able to interpret the data on my scan tool. I thought I knew what it was saying but it turns out I really didn't, until know. I can not tell you how informative the class was. I think I just raised my game.
Hey Bashar, interesting that it has 2 codes stored that are the exact opposite. Start by looking at the fuel trims and see how it's running right now. From there it will give you a direction to go. Mike Becker, Senior Technical Instructor
I have a 5.3 chevy truck bank 1 is lean PO 171 and Bank 2 is rich PO 175 , would these two conditions be the O2 sensors ,MAF sensor ,or a leaky intake gaskets .I did the fuel pressure test ,its at 58 psi and holds pressure,i cleaned the MAF sensor but still comes up with a PO 171 bank 1 lean , PO 175 back 2 rich ,engine runs rough up until its at temp then it runs at idle not too bad but has no power when you step on the gas and back fires and when you bring up the RPM to around 2000 or so it runs really rough.
Brian, see if the 02's are doing their jobs. Force the rich side lean and the lean side rich. If they respond well then they are working. Does the issue get worse the hotter the engine gets? Maybe a plugged up cat issue? Mike Becker, Senior Technical Instructor
I'm trying to get my head around fuel trims. Would I be correct that a vacuum leak would cause the engine to run at a higher idle speed than normal? My logic says it would, but I've never heard of a high idle speed being a symptom of a vacuum leak before. Thanks for your help.
I believe your logic is correct, unmetered air at idle increases fuel delivery from pcm trying to reach 14.7:1 stoichmetric ratio which increases idle.
Hello Mike, I have a question about the fuel test. You demonstrated how check alcohol content in the sample of gasoline. I understand the process and your results. My question is about same test telling you if your sample has a high water content. I would think you fill the container 100ml of gasoline and 20 ml of the water with food coloring. If the fuel was contaminated with too much water. Would the 20 ml section grow in the sample?
Hi Joseph, Yes, the water value would increase. Say the fuel was 20% water..you should see 80ml of fuel then and 40ml of water. The water and alcohol will look and mix the same. Mike Becker, Technical Services Instructor
Hello Mike, The mass air flow sensor was cleaned with throttle body spray. 6 months ago. I would have to test electrically the maf and the MAP ( manifold absolute pressure) sensor too. Do you have a video I can see for these test? I suspect the vacum hoses do I light the propane torch or just gas flow? i WANT TO PARTICIPATE IN YOUR CLASSES HOW DO i DO THIS BEST PLACE TO START? RESPECTFULLY, Alex
Alex, we do not have a specific video on that car. With propane, you just want the gas flow, not lit. As for joining us for our classes, we typically go live the first Thursday of the month. Our next class goes live on August 3rd at 11 am and 2 pm central time. I hope you can make it! Mike Becker, Technical Services Instructor
Excellent vid as usual. Wee Q. Instead of using propane to see a reaction from the o2 sensors could I use acetylene from the garages oxyacetylene? And also, can I put oxygen in intake to lean-off mixture in when o2 is reading rich to confirm o2 is reading properly? Thanks. N/W Scotland.
Fox Brendon, I have heard of people using acetylene, just be SUPER careful. I prefer propane, or even brake clean. As for running it lean, just pull a vacuum hose. It will suck tons of air in and then you can see if it will skew lean. No need to force 02 into it. Mike Becker, Senior Technical Instructor
Wow, thank you for confirming this lesson! Observations to contemplate, when the car starts it does not start with one cycle of the engine, it starts at 3 cycles of the engine rotation. When I turn the car off and walk around the gas compartment their is a definite smell of gasoline vapor round the back. It has a new cap greased up to better seal and pressurize, however it might be time to change the fuel filter? Should I do a compression test for cylinder number 1 where I found lots of carbon build-up?
Alex, fuel smell could be coming from an component in the EVAP system. As for the carbon build up...you can do a compression test sure, but if the cars running ok, i'd leave it be. No sense in trying to find a problem that's not there. Mike Becker, Technical Services Instructor
if the egr is stuck open more inert gas will enter the cylinder which is non combustible causing there to be less oxygen in the cylinder causing a rich condition tech A is right
Same fashion as in petrol ones. Theres unmetered air coming in, engine is out of stoichiometry, ecu not happy so it enters fuel trims - add % more fuel until satisfied.
Hello Mike, It appears that the on board diagnostic tool tester for codes has to be cleared of old codes and the car's pcm computer has to reboot by disconnecting the negative terminal and reconnecting it so that the check engine light disappears. The tester says no codes and the trims are at 0, long term and shor term hover around the zero mark when in idle long term is slightly at -3 and the short trim at -3. Is that a good fix?
Alex, sounds fixed to me! Typically anything you see around 0 is good. You want to for sure see under +/- 10 for the trims. I think it's all fixed up! Mike Becker, Technical Services Instructor
Question: Would short term fuel trim change while in open loop with the propane near the leak? Or does short term fuel trim only kick in once closed loop starts after the car runs for a bit?
Neil, when a car is in open loop its fuel off of base maps that are in the PCM. Closed loop is when fuel trimming occurs. Short term fuel trim will normally read 0 when in open loop. Mike Becker, Senior Technical Instructor
Hi.. could u please help me on my question? When I opened my car bonnet I saw that my O2 sensor - ECU cable has been broken. However this was not shown as a CHECK engine alarm. Does it mean that my ECU does not function properly? Because in my car manual code 21 is for - At a speed of up to 100 km / h and a speed above 1500 rpm, the amplitude of the oscillations of the oxygen sensor OX (OX1) decreases to 0.35 - 0.70 V for a period of 60 s or more. So of my O2 sensor wire was disconnected this should be shown..please advice..
Vidura, unfortunately I am not sure what emissions standards your vehicle is set to. I would agree that an open circuit(wire broken) should set a check engine warning light. Mike Becker, Technical Services Instructor
It would be great if the recorded volume was a bit higher. I can be noisy when we are listing to the video classes. I have the volume at 100 % but still have a hard time catching everything that is said. Thank you.
If your old video has a channel for sound and another one for video you can Reedit the sound channel only and increase the volume. What software do you have? Just curious. Great video content.
A stuck EGR valve will create a referred code lean p0171. It is a false reference code to uneven pressure building up. The why, would be that o2 sensor will it as unmetered air reducing fuel; must cars are set to calibrate towards lean. gases backing up reduce incoming air. I tried this is lots of fun.
it is leaner as tech b said bcz it lowers the temp of engine which reduces complete burning[when engine is not hot enough] which leaves more oxygen for oxygen sensor to detect gives the lean mixture signal to pcm
Great thought, I like it. The correct answer really was either. Because under the correct conditions either situation is possible. Mike Becker, Technical Services Instructor
help 2003 jag x type 3.0 awd. hesitation at low load and low revs fine flat out etc. changed bank 1 o2 sensor 5 times and throws 5 different fault codes.that sensor related, now its a lean code on that bank fuel trim all over the place also. done all vacuum checks changed inlet manifold , injectors, plugs, coils, maf, map, throttle position sensor, throttle body still the same, with a one of faulty o2 sensors p1646 runs fine but all others nope..... wtf!!!!!
Hey John, sounds like you have yourself quite a headache here. Have you checked fuel pressure? That can cause an issue. What does the short and long term trims read? Mike Becker, Senior Technical Instructor
Brake clean is horrible for any intake usage. It strips the oil off the wall and damages the rings. I know from experience. It welded the ring and I had to throw away the pistons. It leaves little pellets of carbon. It's good to clean with. It's an oil cleaner. The put some lube in starter fluid that prevents welding.
I have a personal preference for ATG (Automotive Training Group) books, or visit AESwave.com under the training section. They have an abundance of awesome training info.
Hi Mike, excellent video and approach at diagnosing a fault. I have a lean problem under load, only on Bank 1 and LTFT has got to +25% and set an EML with fault P2196 B1S1 too rich. Any ideas? It happened after I had a new exhaust and sports cats fitted. Could it be an exhaust leak or maybe a clogged injector? Anything I can do to try pin point the problem?
Hi Elderoo, thank you! First of all, what kind of car are you working on? I just want to verify what you have written here. You are saying your LTFT is @ POSITIVE 25% and you are setting a RICH code? Typically in a situation like this, you would see opposite. Like a LEAN code with a +25%. Meaning the computer is adding +25% fuel because it was lean. Or a -25% because it was running rich. Mike Becker, Technical Services Instructor
Hi it's an Audi A3 2007 3.2 V6 and yes fault is Oxygen (Lambda) Sensor B1 S1 P2196 - 002 - Signal too High (Rich) and LTFT is +25 under load on Bank 1. Bank 2 trim is normal. I wondered if it was triggering the rich code because LTFT had maxed out? Really need to get to the bottom of it. Thanks for the reply
Elderoo, that is a strange one. Can you force the sensor the other way. Can you make the LTFT move? What are your STFT on B1? It's hard to know what to trust here. Because you are getting opposites. The code says the engine is rich, the LTFT says it's severely lean. Do you have a full function scanner you can clear codes and reset fuel trims and see what they do? Kinda take a moment to start fresh. I am leaning towards a Lambda sensor issue, but want to prove it first. Mike Becker, Technical Services Instructor
Hi, yes I can clear codes and gradually watch fuel trim increase. At idle it's all pretty normal on both banks but when driven you can see the LTFT increase on Bank 1. It takes about 30 miles to get upto +25% and set the code. I changed the o2 sensor for b1s1 already but it didn't make any difference. Car drives perfectly tho, no hesitation or hunting on idle etc. Fuel economy is slightly down and tail pipes are a little black. Maybe the PCM is picking up a false lean and increasing fuel unnecessarily?
Here is the Freeze Frame Data... PID02 DTC that caused freeze frame data storage: P2196 PID03 Fuel system 1/2 status: Closed loop, using O2 sensors ... Closed loop, using O2 sensors PID04 Calculated load value: 78.0 % PID05 Engine coolant temperature: 59 °C PID06 Short Term Trim - Bank 1: 1.6 % PID07 Long Term Trim - Bank 1: 14.8 % PID08 Short Term Trim - Bank 2: -2.3 % PID09 Long Term Trim - Bank 2: 2.3 % PID12 Engine RPM: 1789 /min PID13 Vehicle speed: 69 km/h PID14 Ignition timing advance for cyl #1: 20.0 Degrees PID15 Intake air temperature: 16 °C PID16 Mass Air Flow: 39.91 g/s PID17 Throttle position sensor: 27.8 % PID18 Secondary Air Status: Atmosphere/off PID31 Time since engine start: 318 s
Nelson, what is a Toyota Hiace? We don't have them in the US. If I can cross it to a US model I can look into it. Send me an email, we can talk through this! Michael.Becker@wellsve.com Mike Becker, Technical Services Instructor
Hey Juergen, I noticed that too. Seems odd that fuel correction is happening before closed loop. Part of me is thinking that the scan tool is just reporting the loop status a bit behind. Mike Becker, Technical Services Instructor
Hello Mr. Mike, I did a propane test, the fuel trim short went from -7 to -25, the engine stalled. O2 sensor rise to 900mv. The higher the short term went negative the more rich engine was leading to a dead state. Does this mean a intake gasket is the issue?
I would say so! You fed the engine with extra fuel, it went rich, the computer tried to take fuel away. I think you have bad gaskets! Mike Becker, Technical Services Instructor
The smoke machine showed no signs of intake gasket leak. The fuel test did not happen because of fuel metal fitting type A and the plastic fitting type B. Did not have tool for type A metal fitting and the plastic fitting just needs two screw drivers to press on and release however what for, if I do not know if a srader valve is underneath it. The fuel fitting tools neither local auto store have it and the manuel, Hayes is not very explicit in its illustrations. I need to get the manufactures manuel for toyota corrola CE 2000. How can I find it?
Alexander, why do a fuel test? Haven't we already confirmed that the intake manifold is allowing fuel past the gasket? Isn't this our diagnosis? Do we need to go further? Mike Becker, Technical Services Instructor
Hello, Mike, in the video you also included a fuel pump test to further determine poor delivery for stuck injectors or a weak pump. I thought this would be good practice. I ordered a new intake gasket its coming in the mail soon. I will report back to you much later when finished replacing it. Mr. Mike you are an awesome teacher, do you have online classes or college you teach on regular basis and how much will it cost me on a monthly basis. Now, I attempted the fuel pump test however ran into a road block, the Toyota has a metal type A fitting round in shape and inserted into the fuel rail locking it, a special tool is needed, no body locally has this tool, so I could not do the test. I love learning and the challenge of facing the car's design which can be filled with difficult space restriction and strange fittings, it takes more time to fix, when the tools are not so familiar. Each car is so individually different, that it awakens a creative heighten perception on how to solve and approach the magnificent machine with a censorial nerve network, its like being a doctor balancing complex processes and indices.. I am further humbled when working on the car and very grateful to your techs. Blessings and gratitude! AG
I need help 04 330i been chasing lean codes and a P0013, both banks ltft was 30+ replaced some more vacuum lines dropped trims to 13+ on ltft at idle drove the car thinking that would help learn on way back home car is turned off then started as I stopped in town at this put there's 20 new miles on car I then proceeded to drive thru to order the wife her drink upon corning building car started acting odd check engine came on before leaving pulled codes p0013 rpm is now fluctuating . I did manage to grab freeze frame however I was being rushed so managed to see the rpm when code was set was 147 however no code for a crank sensor just the exhaust camshaft. I'm thinking an electrical issue maybe ground. Also ltft went to 0 but stft went to +15 after driving so I'm stumped on that as well that was checked with light on . Anyone ?
I have literally changed everything on this car basically all pm items.. battery alternator fuel filter intake gasket tubes etc cleaned tb icv, fuel system cleaned also vanos on car is new unit, car idles perfect and has get up and go
I think stft was high because the cams couldn't adjust as needed at least the exhaust camshaft . I believe my lean codes are good now but I got the p0013 that is intermediate
Try to force the engine lean. Take a vacuum hose off, see if it responds. Maybe you have a stuck oxygen sensor. Mike Becker, Senior Technical Instructor
That's good. Means the 02 sensors can accurately read. So, hows fuel pressure? Within spec? Does it bleed down when the keys shut off, like an injector leak? Mike Becker, Senior Technical Instructor
@@GoTechTraining in spec 45 at idle 50 when you remove the vacuum hose from fpr. Does not bleed down. Evap system working no leaks. Vaccum at back for that system and purge valve up front working and pushing stinky fumes when told too lol. This is a r53 mini cooper. All hardline sunder hood checked nothing leaking. Each line taken off and plugged with 10psi pushed into them. No leak in exhaust. This is a well maintained vehicle. -30 shrt term fuel trims only at idle. Drives fine everywhere else except for tip in as the ecu has pulled max fuel and well is now lean on tip in takes a few seconds for it respond. Idles perfect at 14.7-15.3 afr even at -30. Still something is amiss
My thought- it will indicate Rich. Thinking- exhaust gas has very little oxygen, so the air into the engine will have Less than normal in And out when exhaust is added to the intake. I'm a hobbyist, my own mech and Always learning. In lew of a smoke machine & tester I add trace refrigerant and use my leak checker! Bwaa haa haa!
Hello Mike, I keep looking for a notice from wells tech about the next class, I have missed some perhaps, I don't know. I have trouble navigating the tech wells website, looking for love classes. Respectfully, AG
Hey Alex, I have not published anything yet on when the next class will be. That being said, it will be on Sept 7th at 11 am central time. Thanks! Mike Becker, Technical Services Instructor
Sure, the PCM could the culprit in many different diags...but I wouldn't jump to that conclusion. Maybe take this thing in somewhere? Mike Becker, Senior Technical Instructor
That was a GREAT demonstration with the E85 gas, especially with the blue coloring additive, but it didn't seem obvious why you were doing all those ethanol tests in the first place. The title of your video is "Fuel Trims-Testing & Diagnosing Rich and Lean Conditions", but you don't mention how ethanol impacts fuel trim. In a future video you may want to discuss that, along with the effects on fuel trim due to ambient temperature extremes, summer vs winter fuel blends, humidity, barometric pressure, variances in octane, etc. Keep in mind too that Trump is threatening to legalize E15 everywhere to gain brownie points in the cornbelt. If that happens, it's going to cause some trouble with older cars, especially older cars in disrepair, who's fuel trims are already close to the CEL limit.
Hey Jay, thanks for watching! If I remember right, the point of that part was to test for water/ethanol in the fuel when diagnosing rich/lean conditions. The goal wasn't to explain what happens when there's ethanol present, just that it's a test to perform when checking for it. I believe it was one or 2 classes prior to this one I went into explaining what happens with ethanol in fuel. Mike Becker, Senior Technical Instructor
im am by far not a drinker, im a smoker, but i do know that alcohols the only thing that has "legs" and that glass u were talkin about thats supposed to b premium fuel definitely had some self sustaining legs, they werent huge but definitely there
Choice is yours Terry. There are a lot of factors that lead up to that decision. Check out this video we did on O2 sensors. Should help in making your decision. ua-cam.com/video/wZc-zCr2QnE/v-deo.html Mike Becker, Technical Services Instructor
Hey Darren, it's pretty free to take as much time as needed. I try to keep them down to around an hour and a half. Once you go much longer you really start losing people. It really all depends on the lesson though. Mike Becker, Senior Technical Instructor
Eric, on the question from Fox Brenton asking you about acetylene. We need to be careful here, Remember acetylene EXPLODES at the presence of OIL. I had the experience of gas and carb cleaner exploding on me. Gas on my face and propane a few feet away when checking for leaks, needless to say gas is nastier (sudden long flame) than propane (sudden flash) I do not want to be there when acetylene explodes. Definitely NOT RECOMMENDED.
Great comment! Any sort of flammable gas should be used in extreme caution. Propane is the ideal choice for these situations. Mike Becker, Senior Technical Instructor
It is the oxygen side of the oxy acetylene torch set up that reacts to the oils in an explosive way (petroleum based lubes). This is the same chemical reaction when those commercial jet blew up and crashed. It was hauling oxygen generators the had a compressor leak ( refrigerant oil was exposed to the pure oxygen casing an explosion. Granted-the acytlene is very farmable but lacks the explosive ability on its own but if you mix in the oxygen till you have a neutral flame and snuff it out the explosive /unstableness potential of the acetylene increases incredibly and will explode with the slightest exposure to excessive heat or a small spark . But if you were to expose that pure oxygen to oil that may be the first and last time that you will ever be able to try that experience again🪦
Hell mike, The intake manifold is a fix however I never reported that the car is experiencing hard starting, after a few cranks it starts not like it did before. Is it fuel regulator and fuel filter non of which I can immediately see?
Hey Alex, sorry it took so long to get back to you. So, does this only happen after the car sits for a bit? Does this happen if you shut it off, and try to restart it right away, or does it need to sit for a few hours? It could be the check valve in the fuel pump assembly. The fuel pressure could be draining back out of the rail and causing your extended cranking time because the pump needs to refill the rail every time. Mike Becker, Technical Services Instructor
Hello Mike, Hard starting happens all the time yet I had forgotten to mention that I had replaced old injectors with new injectors. The old injectors worked fine car immediately started all the time until injectors were replace, so I remove new injectors and noticed the rubber seats were bigger then the originals seats at the base. the o rings on top all matched. Now the car starts right up instantly however the check engine light is back on and the diagnostic devise read code P0171 lean bank one. The live data long term fuel trim reads 0.80; short term reads 00 or drops to -3 then up to zero on idle. O2 sensor reads 0.40 to 0.300 to 0.600 to 0.800 on idle. mass air flow sensor reads 235 on idle sprayed vaccum hoses with water no reaction to idle. I will have to read about the check valve apparently the fuel regulator ; check valve and filter are all in one unit inside the fuel tank. The car runs well and has power, the check engine light is on when disconnecting the battery negative lead the check engine light is gone and the diagnostic reads no codes pending. However while driving at high speeds for an hour the check light returns again. This situation intrigues my curiosity. Is this codes P0171 a false code making a reference to something else? Are my new injectors defective or one of them. I listened to the injector with a stethoscope then sound very close in vibration. Should i use a garden hose to flood the manifold with water to hear any changes in idle speeds? It may not be the check valve yet it would be good to examine it with volt meter? Again many thanks, I was surprise to receive your email response. Respectfully, Alexander Gonzalez.
Hey Alex, looks like we are back to a lean code. Which is just saying there is too much O2 going past our sensor. So, do we not have enough fuel? Do we have too much air? I would not advise flooding the engine with a hose. I would much rather use propane or something like that to look for a vacuum leak. I can't remember, is the MAF new, or cleaned? That may be something to look at. Mike Becker, Technical Services Instructor
Hello Mike, reporting that I have used the propane gas and brake fluid upon starting engine from cold to warm just before it heats to high temperature, so far no systems of a leak. Check all the hoses, they seem to be snug tight. I suspect the brake cylinder vac um, only because when braking the pedal pressure weakened, ti happened once. I also suspect the posit crank case valve, it has not been cleaned out in 2years. The car runs well, i have disconnect the battery negative cable, 5 mins to make check engine light disappear after 8 days of high speed driving the check engine light come back on, its just amazing. This Makes me believe the the code P0171 LEAN CONDITION IS FALSE OR A REFERRED CODE TO SOMETHING ELSE HAPPENING or its just a faulty diagnostic computer from harbor freight, that is defective, who knows? this check engine light came back when I had taking out the new fuel injector to re-use old injectors, could be a cracked injector or poor rubber seal rings? Respectfully, Alex G.
47:10 chunk missing,another chunk missing... bad material, the money light on, and people pay good money for this; Also, you have to make absolutely sure that those "blue" rings stay well captioned in their nests when you assemble the whole shibang,you can't see them as you lower the manifold;
Hola Celerino, Estamos haciendo esta misma clase en español LIVE el miércoles, 19 de abril a las 11am y 2pm hora central. Espero que te veamos allí. Mike Becker, Technical Services Instructor
Gotta get that extra power any way you can right? Ahhh a Monaro. I knew Holden made it, just couldn't remember the model name. Thanks tecnaman! Mike Becker, Technical Services Instructor
But EGR is not oxygen, it's inert. So what does that do to our oxygen content? And what do you mean by it reading high? Like high voltage? Mike Becker, Technical Services Instructor
![Short Term and Long Term Fuel Trims Explained [Easily]](http://i.ytimg.com/vi/IuM53mlOgHs/mqdefault.jpg)
I’m a Nissan Master technician. 25 years experience. Your video’s are the best I’ve seen on UA-cam. Keep it up!!
Thanks MrJoeyB!!! Glad you're lovin on classes! :)
Mike Becker, Technical Services Instructor
Hey Mr Joey sorry to ask but i have a 03 pathfinder that i completely rebuilt the vq35de in it last year down to regrind and cylinder hone. compression is 185-195 between all cylinder after rebuild. Was having a intermittent hard start last week that was fixed with a fuel pressure reg and dampner along with a new fuel pump. my LTFT are right at -5.5 on both banks. shouldnt they be closer to 0 - +/-1?
came over from SMA, very informative video, thanks.
Hey thanks Jack!
Mike Becker, Senior Technical Instructor
Marie sent me over with the rest of the crowd.
Subbed.
Nice! Welcome :)
Mike Becker, Senior Technical Instructor
Miss Marie and Eric O sent me here and you got a new sub. Great channel
Joe Bellanger me to. Good video
Hey Joe, welcome, thanks!
Mike Becker, Senior Technical Instructor
Great video. I had this same diagnosis based off the pids. Fuel trims with readings alone with both banks were a clear indication. Reading active O2 would have also pointed that direction. Could have also looked for a lack of fuel but considering least intrusive diagnostics first the Vac leak is the most likely culprit with the easiest tests to verify.
Thanks for watching!
Good video and helpful to see actual diagnostic readings from the car - recommend.
I realise the video is old and that competition is finished long time ago but i'd like to verify my answer. Answer:
A stuck open EGR will throw a lean code because a stuck open EGR is basically a huge vacuum leak, letting massive amounts of unmetered air going into the engine which will obviously be detected by 02 causing the ECU to call for more fuel. Thank you for your time
Hey Rok, thanks for trying at the question anyway. I respond with a question...is an EGR being stuck open a vacuum leak? How much oxygen is in EGR gas? ;)
Mike Becker, Senior Technical Instructor
Hello, just to (try)answer your questions. EGR sits between exhaust and intake manifold, right? Therefore, a stuck open EGR will create a vacuum leak by allowing the air from intake to escape, at least partially. As for the second question, there would be none or very little, and i know that you've mentioned that in the video.
Thank you
I have a 02 f150 4.2 with a bank 1&2 sensor one both sides.
I have done an intake job reseal.
Also did a timing cover replacement and replace synchronizer .
Also changed MAF because of damage to the MAF
Hi miss Marie sent me
Sweeeeeeeeet :)
Mike Becker, Senior Technical Instructor
@@kenrhodes8132 same for me
Add me to the list. Miss Marie said hello
Me 4!
She's doing a great job learning!
Have you watched her video on SMA?
New sub here!
Me too. Though I already watched and loved your Audi brake booster video
Stuck open EGR on MAF will skew MAF reading makeing that system runing lean. We call it inside air leak, the sneaky pirate.
Heres firsth video that i did find for EGR with MAF and its from Paul Danner so yeah. ua-cam.com/video/zIZCbn7aaME/v-deo.html
I personaly have never sean car that runs rich as EGR is open but then again 99% cars that i see in front of me have MAF engine in them.
Thanks for watching! I like that, the sneaky pirate!
Mike Becker, Senior Technical Instructor
Great video. Do you know what ECU does in the presence of one P017... code? It will run a programmed map or will continue to use o2 sensors and others? What i understood it is that when P017... occurs the ECU knows that a problem exist but can not identify the cause. I hope i am right. Thank you.
Ms Marie from South Main Auto recommended. Very good...even for those of us who are just hobbyists rather than professionals. Beautifully explained. Very helpful.
Hey Mark, thanks and welcome!
Mike Becker, Senior Technical Instructor
Tech B is correct due to the valve stuck open in this instance its letting more fumes pass than being calculated and it is acting like a vacuum leak and is a continuous flow of gasses.
Rookie mistake in which I did learn from keep them coming super great video.
Hahah glad you got it now! Thanks for watching.
Mike Becker, Senior Instructor
Hahaha love the "don't think that's measured in ugga duggas" comment! Great videos guys, I'm a DIY'er but I've learned more about closed loop fuel systems and related sensors in your last couple of videos than I ever thought was necessary - but now it's clear that it is.
Hey Landis, thanks for watching! Information is power :)
Mike Becker, Senior Technical Instructor
What do you check if the BARO is not correct? Hyundai Tucson we were looking at had P0171 & P0174 and no vac leaks and BARO was showing 23inHg with KOEO and with vehicle running (local BARO 30inHg)...no change when unplugging the IAT or MAF sensor...could not located a specific BARO sensor on the vehicle and ALL-Data did not show a sensor location (i believe it is integrated into the MAF). 2008 Hyundai Tucson 2.7L. The PCM was adding as much as 25-31.8% on both Banks...sometimes was throwing a P0170 & P0173 code also.
I actually can't remember if I was monitoring the BARO PID when I unplugged the MAF. I should also add that vehicle seem to run worse with MAF unplugged, and no noticeable change in running condition w/ IAT unplugged. All 4 O2 sensors seemed to be working correctly from the live data but sometimes seemed slow to respond. No O2 sensor codes tho, and that may have been my tablet just running slow on updating the live data which it seems to do if I am graphing 4 PIDS at once. All 4 oxygen sensors showed close to 450mV w/ KOEO. They were usually like ~410-430mV actually. When you fire it up, the upstreams do start switching when it enters CL but the downstreams go hard lean then the STFT go hard positive +31% then as the LTFT pick up the slack the STFT drop to +10-15% ish. Everything in my experience was pointing towards vacuum leak but we checked with spraying carb cleaner w/ engine running near potential vac leak areas as well as testing for vac leaks w/ a smoke machine...neither way found any leaks. I thought maybe low fuel pressure, because it something affecting both banks. Unfortunately my scan tool wont pull fuel rail pressure data and the vehicle does not appear to have a typical schrader style valve to test the pressure directly. After one of the many times of clearing and resetting everything during 2 days of testing it just didn't do it, it didn't pull any codes, the fuel trims all seemed good. And no CEL, i was shocked... So i went and test drove it and the readiness monitors were checking off one by one and I thought, IDK this thing might have just fixed itself. I only needed 1 more readiness monitor to get it to pass SI (you can have 1 not ready, it had 2) and before either of them popped to ready....dayum MIL came back on and pulled System too lean bank 1 & 2 again. This one is really giving me trouble, if anyone can help.
I checked and found a TSB about the air intake box sometimes being an issue, followed TSB instructions and verified it was not our problem...we did other testing too that I am sure I can't remember right now...but any input from anyone would really be appreciated. I am at a total loss here.
There is never any detailed fuel trim videos on rich trim. I've replaced IAT, 02's, CT, MAF, MAP, N80 purge valve, i've tested for vacuum leaks, checked the FPR Cannot get rid of the rich fuel trim.
Rich conditions are less common than lean but can be diagnosed the same way. Force the engine lean, do the trims and 02's react accordingly? How's fuel pressure after the key is shut off? Maybe a leaky injector?
Mike Becker, Senior Technical Instructor
Hello Mike,
Remove air intake manifold, discovered piston #1-, its air port, had carbon build-up in gobbles.
Replaced the gasket torque it to 13.666 inch lbs, checked fuel trims: long term was higher 10 mv idling, on acceleration it when up to 39.45 mv.
short term, was -8 to -15 idling, on acceleration it dropped to zero and to .5 mv
I re-torqued the manifold while hot, the long term is now stable at 2.3 mv
short term between -5 to -14 while idling.
accelerating while driving the shorterm is stable between 2.3 to .5 mv
short term moved to positive 5.
deceleration drops to 00 to -.1 to -.5 to -.10 it stays on the ten.
removed spark plugs very clean no fouling, replaced with new sparks.
injectors replaced too.
checked with stethoscope all injectors sound good crispy and tight. the spark plug sound chirpy good frequency. however the piston chamber # 1 sound like weak oil rings, other piston sound clean and clear.
Could the short term trims stable at -10; long term stable at 2.3 is this a sign of low compression?
Oil was changed added 3.75 quarts after driving for one hour the next day checked oil it lost .25 oz it could be burning oil yet no signs of it coming out of exhaust pipe.
checked vaccum with pump its at 22lbs perfect.
check engine light is still on, I did not remove battery cable while working on it. Should I remove battery cable wait 3 minutes and re-connect it to see if the check engine light disappears?
The on board computer tester still brings up code P0171.
There was a pending code P0125 throttle position senor, thats because i did not tighten the bracket to ground enough it gone now after tightening its bracket to engine block.
Thank for the video. Could you help me make sense of these STFT and LTFT values. I have 07 ford taurus, for bank 1 STFT stays between +/-3%, but LTFT stays constant at about -12% at Idle. Bank 2 is lean at idle with +12% total fuel trim. When I increase RPM to 2500, STFT jumps between +/-6% and LTFT stays constant at -19%. Bank 2 improves at 2500 RPM with about +6% total fuel trim. OBD says cylinder 1,2, and 6 misfire. I have tested injectors, replaced the leaking injector already. What do these trim value mean? How come bank 1 is rich and bank 2 is lean? Thank you.
Does the engine have any other trouble codes? Something is causing the engine to run lean on one and rich on the other bank. Has the timing chain ever been off?
Mike Becker, Senior Technical Instructor
@@GoTechTraining Thanks for the response. Currently, I only get 1,2,6 cylinder misfire codes when I erase the codes. In October 2019, after I reset ECM by disconnecting battery terminal, I did get P0420 and P0430 pending codes saying "catalyst system efficiency below thresold for both banks". I checked freeze frame data screenshots I took that time. LTFT on bank 1 was -14.1, and +3.1 on bank 2. STFT 1 was -1.6 and STFT2 was +1.6. From research, the rich condition on bank1 and lean condition on bank 2 eliminates some possibilities like vaccum leak, bad MAF, leaking egr valve, ECT sensor, fuel pressure regulator. there might be vaccum leak on just bank 2 but I am not sure how that could be possible since both banks are fed same way.
So for rich condition, the remaining culprits are:
1) bad O2 sensor O2S1B1 (which seems to be working since it jumps between 0.1-0.85V)
2) Spark plugs on bith banks (I replaced spark plugs in December last year, so I am not sure if its bad, I am planning to check them tomorrow).
3) leaking fuel injectors (less likely because, when I saw cylinder 1,2 misfire last time I swapped them with cylinder 4,5, now there is still cylinder 1,2 misfire)
4) Catalytic converter (not sure since there is no rotten egg smell, just exhaust fume out of tail pipe)
5) Exhaust leak (I smell exhaust fume in cabin whenever I start AC or heater, I think there is exhaust leak. I have to check both banks exhaust system for leak, but not sure whether it should cause rich or lean condition)
Do you think the exhaust leak is due to plugged catalytic converter? Do you think its the main culprit? Please let me know if I am checking things right way. Thank you very much
Ms. Marie from SMA sent me because apparently you're awesome.
Hahah I don't know about that. I'll let you formulate your own opinion!
Mike Becker, Senior Technical Instructor
The EGR stuck open would cause a lean code because the air entering the intake manifold would be unmetered... not being metered by the mass airflow sensor would throw off the fuel trim to lean... letting in more air than fuel...
Thanks a lot for your videos and sharing your knowledge. I have a fault that both banks mixture are too rich. I checked the long term fuel trim (LTFT) using a cheap code reader, I found that on high way the LTFT is between 0 and -5%. When it's on idle or when I remove my feet on the accelerator pedal, it becomes really rich -20 to -25%. I bought a used MAF from the scrap and installed it but the problem persists. From your experience what can be the problem? Both banks have the problem, so I would rule out the injector leaking or spark plugs. I have a C250 4 matic V6 2012 gasoline. Thanks a lot
Hey 80goal, i'd be curious as to what the fuel pressure sensor reads. Maybe that reading is skewed and the fuel pressure is too high? Nothing is really common to that engine. Wish I had more to go off of for you.
Mike Becker, Senior Technical Instructor
Guys, Thank You. It is awesome being able to interpret the data on my scan tool. I thought I knew what it was saying but it turns out I really didn't, until know. I can not tell you how informative the class was. I think I just raised my game.
Hey Bryan, thank you so much! Glad we could help raise up your game.
Mike Becker, Senior Instructor
Hi, My car is Corolla 2009 and it always appear the booth SYSTEM TOO LEAN (BANK 1) & SYSTEM TOO RICH (BANK 1) ... any help please ??
Hey Bashar, interesting that it has 2 codes stored that are the exact opposite. Start by looking at the fuel trims and see how it's running right now. From there it will give you a direction to go.
Mike Becker, Senior Technical Instructor
The video Picture is not matching with the sound?
Ms Marie recommended this vid.
Awesome Spunkmire!
Mike Becker, Senior Technical Instructor
That’s why I’m here
I have a 5.3 chevy truck bank 1 is lean PO 171 and Bank 2 is rich PO 175 , would these two conditions be the O2 sensors ,MAF sensor ,or a leaky intake gaskets .I did the fuel pressure test ,its at 58 psi and holds pressure,i cleaned the MAF sensor but still comes up with a PO 171 bank 1 lean , PO 175 back 2 rich ,engine runs rough up until its at temp then it runs at idle not too bad but has no power when you step on the gas and back fires and when you bring up the RPM to around 2000 or so it runs really rough.
Brian, see if the 02's are doing their jobs. Force the rich side lean and the lean side rich. If they respond well then they are working. Does the issue get worse the hotter the engine gets? Maybe a plugged up cat issue?
Mike Becker, Senior Technical Instructor
Hey Mike. Miss Marie sent me. Feels like deja vu...lol.
Hey Mike, welcome back :) haha!
Mike Becker, Senior Technical Instructor
Video is out of sync with audio for me too
Works fine on my phone though. Weird
@@jabenton1987 issue on my phone but will try another device. Haven't had any issues with 3 other videos.
I'm trying to get my head around fuel trims. Would I be correct that a vacuum leak would cause the engine to run at a higher idle speed than normal? My logic says it would, but I've never heard of a high idle speed being a symptom of a vacuum leak before. Thanks for your help.
I believe your logic is correct, unmetered air at idle increases fuel delivery from pcm trying to reach 14.7:1 stoichmetric ratio which increases idle.
Hello Mike, I have a question about the fuel test. You demonstrated how check alcohol content in the sample of gasoline. I understand the process and your results. My question is about same test telling you if your sample has a high water content. I would think you fill the container 100ml of gasoline and 20 ml of the water with food coloring. If the fuel was contaminated with too much water. Would the 20 ml section grow in the sample?
Hi Joseph, Yes, the water value would increase. Say the fuel was 20% water..you should see 80ml of fuel then and 40ml of water. The water and alcohol will look and mix the same.
Mike Becker, Technical Services Instructor
Hello Mike,
The mass air flow sensor was cleaned with throttle body spray. 6 months ago. I would have to test electrically the maf and the MAP ( manifold absolute pressure) sensor too. Do you have a video I can see for these test?
I suspect the vacum hoses do I light the propane torch or just gas flow?
i WANT TO PARTICIPATE IN YOUR CLASSES HOW DO i DO THIS BEST PLACE TO START?
RESPECTFULLY,
Alex
Alex, we do not have a specific video on that car. With propane, you just want the gas flow, not lit. As for joining us for our classes, we typically go live the first Thursday of the month. Our next class goes live on August 3rd at 11 am and 2 pm central time. I hope you can make it!
Mike Becker, Technical Services Instructor
Oh yes, I will plan it, thank you!
Great! See you then!
Mike Becker, Technical Services Instructor
Excellent vid as usual.
Wee Q. Instead of using propane to see a reaction from the o2 sensors could I use acetylene from the garages oxyacetylene? And also, can I put oxygen in intake to lean-off mixture in when o2 is reading rich to confirm o2 is reading properly?
Thanks.
N/W Scotland.
Fox Brendon, I have heard of people using acetylene, just be SUPER careful. I prefer propane, or even brake clean. As for running it lean, just pull a vacuum hose. It will suck tons of air in and then you can see if it will skew lean. No need to force 02 into it.
Mike Becker, Senior Technical Instructor
Hello! Good Morning! Ms Marie sent me here!
I have done all this and still have code what else is there that could make this code supercharger valve or what
Check out the video I have with the Audi, it shows some more stuff you can check out.
Mike Becker, Senior Technical Instructor
I am staring to be familiar with fuel trims with your clear presetation
Awesome Lino! Glad it's helping.
Mike Becker, Senior Instructor
Oh and good job keeping Ms Marie attention. Good thing you wasn't walking through it like a brake job.
Haha thanks man!
Mike Becker, Senior Technical Instructor
Wow, thank you for confirming this lesson!
Observations to contemplate, when the car starts it does not start with one cycle of the engine, it starts at 3 cycles of the engine rotation.
When I turn the car off and walk around the gas compartment their is a definite smell of gasoline vapor round the back. It has a new cap greased up to better seal and pressurize, however it might be time to change the fuel filter?
Should I do a compression test for cylinder number 1 where I found lots of carbon build-up?
Alex, fuel smell could be coming from an component in the EVAP system. As for the carbon build up...you can do a compression test sure, but if the cars running ok, i'd leave it be. No sense in trying to find a problem that's not there.
Mike Becker, Technical Services Instructor
if the egr is stuck open more inert gas will enter the cylinder which is non combustible causing there to be less oxygen in the cylinder causing a rich condition tech A is right
Can you apply fuel trims to diesel engines? thank you
In what manner?
Mike Becker, Senior Technical Instructor
Same fashion as in petrol ones. Theres unmetered air coming in, engine is out of stoichiometry, ecu not happy so it enters fuel trims - add % more fuel until satisfied.
Hello Mike,
It appears that the on board diagnostic tool tester for codes has to be cleared of old codes and the car's pcm computer has to reboot by disconnecting the negative terminal and reconnecting it so that the check engine light disappears. The tester says no codes and the trims are at 0, long term and shor term hover around the zero mark when in idle long term is slightly at -3 and the short trim at -3. Is that a good fix?
Alex, sounds fixed to me! Typically anything you see around 0 is good. You want to for sure see under +/- 10 for the trims. I think it's all fixed up!
Mike Becker, Technical Services Instructor
Question: Would short term fuel trim change while in open loop with the propane near the leak? Or does short term fuel trim only kick in once closed loop starts after the car runs for a bit?
Neil, when a car is in open loop its fuel off of base maps that are in the PCM. Closed loop is when fuel trimming occurs. Short term fuel trim will normally read 0 when in open loop.
Mike Becker, Senior Technical Instructor
Hi.. could u please help me on my question? When I opened my car bonnet I saw that my O2 sensor - ECU cable has been broken. However this was not shown as a CHECK engine alarm. Does it mean that my ECU does not function properly? Because in my car manual code 21 is for - At a speed of up to 100 km / h and a speed above 1500 rpm, the amplitude of the oscillations of the oxygen sensor OX (OX1) decreases to 0.35 - 0.70 V for a period of 60 s or more. So of my O2 sensor wire was disconnected this should be shown..please advice..
Vidura, unfortunately I am not sure what emissions standards your vehicle is set to. I would agree that an open circuit(wire broken) should set a check engine warning light.
Mike Becker, Technical Services Instructor
It would be great if the recorded volume was a bit higher. I can be noisy when we are listing to the video classes. I have the volume at 100 % but still have a hard time catching everything that is said. Thank you.
Hey Richard, we have corrected this on more recent videos. Thanks for watching and commenting!
Mike Becker, Technical Services Instructor
If your old video has a channel for sound and another one for video you can Reedit the sound channel only and increase the volume. What software do you have? Just curious. Great video content.
What may be the cause of a 6 Cylinder engine with a lean condition on 1,2,3 cylinders and a rich condition on 4,5,6 cylinders?
A stuck EGR valve will create a referred code lean p0171. It is a false reference code to uneven pressure building up. The why, would be that o2 sensor will it as unmetered air reducing fuel; must cars are set to calibrate towards lean. gases backing up reduce incoming air. I tried this is lots of fun.
What would make it stick at -10.9 new 02 only thing I can see is that the value cover seal is cracked would thay make it run rich
it is leaner as tech b said bcz it lowers the temp of engine which reduces complete burning[when engine is not hot enough] which leaves more oxygen for oxygen sensor to detect gives the lean mixture signal to pcm
Great thought, I like it. The correct answer really was either. Because under the correct conditions either situation is possible.
Mike Becker, Technical Services Instructor
help 2003 jag x type 3.0 awd. hesitation at low load and low revs fine flat out etc. changed bank 1 o2 sensor 5 times and throws 5 different fault codes.that sensor related, now its a lean code on that bank fuel trim all over the place also. done all vacuum checks changed inlet manifold , injectors, plugs, coils, maf, map, throttle position sensor, throttle body still the same, with a one of faulty o2 sensors p1646 runs fine but all others nope..... wtf!!!!!
Hey John, sounds like you have yourself quite a headache here. Have you checked fuel pressure? That can cause an issue. What does the short and long term trims read?
Mike Becker, Senior Technical Instructor
Brake clean is horrible for any intake usage. It strips the oil off the wall and damages the rings. I know from experience. It welded the ring and I had to throw away the pistons. It leaves little pellets of carbon. It's good to clean with. It's an oil cleaner. The put some lube in starter fluid that prevents welding.
What books can I go to to learn
Short term long term, open and close loop, live data, sensors etc? Thanks
Hey James, I don't really know of any books. Sorry. Maybe do a Google search?
Mike Becker, Senior Technical Instructor
I have a personal preference for ATG (Automotive Training Group) books, or visit AESwave.com under the training section. They have an abundance of awesome training info.
Did i miss the rich code diagnostic?
Miss Marie from SMA sent me.
Awesome Jeff, welcome!
Mike Becker, Senior Technical Instructor
Hi Mike, excellent video and approach at diagnosing a fault. I have a lean problem under load, only on Bank 1 and LTFT has got to +25% and set an EML with fault P2196 B1S1 too rich. Any ideas? It happened after I had a new exhaust and sports cats fitted. Could it be an exhaust leak or maybe a clogged injector? Anything I can do to try pin point the problem?
Hi Elderoo, thank you! First of all, what kind of car are you working on? I just want to verify what you have written here. You are saying your LTFT is @ POSITIVE 25% and you are setting a RICH code? Typically in a situation like this, you would see opposite. Like a LEAN code with a +25%. Meaning the computer is adding +25% fuel because it was lean. Or a -25% because it was running rich.
Mike Becker, Technical Services Instructor
Hi it's an Audi A3 2007 3.2 V6 and yes fault is Oxygen (Lambda) Sensor B1 S1
P2196 - 002 - Signal too High (Rich) and LTFT is +25 under load on Bank 1. Bank 2 trim is normal. I wondered if it was triggering the rich code because LTFT had maxed out? Really need to get to the bottom of it. Thanks for the reply
Elderoo, that is a strange one. Can you force the sensor the other way. Can you make the LTFT move? What are your STFT on B1? It's hard to know what to trust here. Because you are getting opposites. The code says the engine is rich, the LTFT says it's severely lean. Do you have a full function scanner you can clear codes and reset fuel trims and see what they do? Kinda take a moment to start fresh. I am leaning towards a Lambda sensor issue, but want to prove it first.
Mike Becker, Technical Services Instructor
Hi, yes I can clear codes and gradually watch fuel trim increase. At idle it's all pretty normal on both banks but when driven you can see the LTFT increase on Bank 1. It takes about 30 miles to get upto +25% and set the code. I changed the o2 sensor for b1s1 already but it didn't make any difference. Car drives perfectly tho, no hesitation or hunting on idle etc. Fuel economy is slightly down and tail pipes are a little black. Maybe the PCM is picking up a false lean and increasing fuel unnecessarily?
Here is the Freeze Frame Data...
PID02 DTC that caused freeze frame data storage: P2196
PID03 Fuel system 1/2 status: Closed loop, using O2 sensors
... Closed loop, using O2 sensors
PID04 Calculated load value: 78.0 %
PID05 Engine coolant temperature: 59 °C
PID06 Short Term Trim - Bank 1: 1.6 %
PID07 Long Term Trim - Bank 1: 14.8 %
PID08 Short Term Trim - Bank 2: -2.3 %
PID09 Long Term Trim - Bank 2: 2.3 %
PID12 Engine RPM: 1789 /min
PID13 Vehicle speed: 69 km/h
PID14 Ignition timing advance for cyl #1: 20.0 Degrees
PID15 Intake air temperature: 16 °C
PID16 Mass Air Flow: 39.91 g/s
PID17 Throttle position sensor: 27.8 %
PID18 Secondary Air Status: Atmosphere/off
PID31 Time since engine start: 318 s
I need the toyota hiace 2015 ,2kd,ftv,engine .the ecu pin out socket designation?
Nelson, what is a Toyota Hiace? We don't have them in the US. If I can cross it to a US model I can look into it. Send me an email, we can talk through this! Michael.Becker@wellsve.com
Mike Becker, Technical Services Instructor
Good stuff on the fuel gage very well explained.
Thanks man!
Mike Becker, Senior Instructor
What if bank 1 has negative 20 short and long trims and bank 2 has positive 20 short and long term trims
Subscribed. Miss Marie from SMA sent me.
Thanks and welcome!
Mike Becker, Senior Technical Instructor
How come you get short term fuel correction (17.50) before the computer enters closed loop???
Hey Juergen, I noticed that too. Seems odd that fuel correction is happening before closed loop. Part of me is thinking that the scan tool is just reporting the loop status a bit behind.
Mike Becker, Technical Services Instructor
Second fuel test you must add 18 ml water to compensate evaporation of fuel from previously 100 ml fuel at measure cup which is now 90 ml.
Hello Mr. Mike,
I did a propane test, the fuel trim short went from -7 to -25, the engine stalled. O2 sensor rise to 900mv. The higher the short term went negative the more rich engine was leading to a dead state. Does this mean a intake gasket is the issue?
I would say so! You fed the engine with extra fuel, it went rich, the computer tried to take fuel away. I think you have bad gaskets!
Mike Becker, Technical Services Instructor
The smoke machine showed no signs of intake gasket leak. The fuel test did not happen because of fuel metal fitting type A and the plastic fitting type B. Did not have tool for type A metal fitting and the plastic fitting just needs two screw drivers to press on and release however what for, if I do not know if a srader valve is underneath it. The fuel fitting tools neither local auto store have it and the manuel, Hayes is not very explicit in its illustrations. I need to get the manufactures manuel for toyota corrola CE 2000. How can I find it?
Alexander, why do a fuel test? Haven't we already confirmed that the intake manifold is allowing fuel past the gasket? Isn't this our diagnosis? Do we need to go further?
Mike Becker, Technical Services Instructor
Hello, Mike, in the video you also included a fuel pump test to further determine poor delivery for stuck injectors or a weak pump. I thought this would be good practice. I ordered a new intake gasket its coming in the mail soon. I will report back to you much later when finished replacing it.
Mr. Mike you are an awesome teacher, do you have online classes or college you teach on regular basis and how much will it cost me on a monthly basis.
Now, I attempted the fuel pump test however ran into a road block, the Toyota has a metal type A fitting round in shape and inserted into the fuel rail locking it, a special tool is needed, no body locally has this tool, so I could not do the test.
I love learning and the challenge of facing the car's design which can be filled with difficult space restriction and strange fittings, it takes more time to fix, when the tools are not so familiar. Each car is so individually different, that it awakens a creative heighten perception on how to solve and approach the magnificent machine with a censorial nerve network, its like being a doctor balancing complex processes and indices..
I am further humbled when working on the car and very grateful to your techs. Blessings and gratitude!
AG
Alexander, We only offer training out on UA-cam like this. All of our training is free!!!
Mike Becker, Technical Services Instructor
Thank you for your time and knowledge
Hey Naz 777, thanks for watching!
Mike Becker, Senior Technical Instructor
I need help 04 330i been chasing lean codes and a P0013, both banks ltft was 30+ replaced some more vacuum lines dropped trims to 13+ on ltft at idle drove the car thinking that would help learn on way back home car is turned off then started as I stopped in town at this put there's 20 new miles on car I then proceeded to drive thru to order the wife her drink upon corning building car started acting odd check engine came on before leaving pulled codes p0013 rpm is now fluctuating . I did manage to grab freeze frame however I was being rushed so managed to see the rpm when code was set was 147 however no code for a crank sensor just the exhaust camshaft. I'm thinking an electrical issue maybe ground. Also ltft went to 0 but stft went to +15 after driving so I'm stumped on that as well that was checked with light on . Anyone ?
I have literally changed everything on this car basically all pm items.. battery alternator fuel filter intake gasket tubes etc cleaned tb icv, fuel system cleaned also vanos on car is new unit, car idles perfect and has get up and go
Interesting. Have you inspected the mechanical timing? Timing chain stretch maybe?
Mike Becker, Senior Instructor
I replaced the vanos 300 miles ago used proper tools to lock cams and flywheel at tdc chain seems good .
I think stft was high because the cams couldn't adjust as needed at least the exhaust camshaft . I believe my lean codes are good now but I got the p0013 that is intermediate
And thank you and the channel as I have learned alot about fuel trims that I couldn't understand from anyone else
I would change those knock sensors, put some grease around them, keep water out ;)
Hey Smokey88, Super common issue on that engine, right?!
Mike Becker, Senior Instructor
What if it was a 0172 and was at idle -30 shrt trm
Try to force the engine lean. Take a vacuum hose off, see if it responds. Maybe you have a stuck oxygen sensor.
Mike Becker, Senior Technical Instructor
It does compensate when I pull brake booster line.
That's good. Means the 02 sensors can accurately read. So, hows fuel pressure? Within spec? Does it bleed down when the keys shut off, like an injector leak?
Mike Becker, Senior Technical Instructor
@@GoTechTraining in spec 45 at idle 50 when you remove the vacuum hose from fpr. Does not bleed down. Evap system working no leaks. Vaccum at back for that system and purge valve up front working and pushing stinky fumes when told too lol. This is a r53 mini cooper. All hardline sunder hood checked nothing leaking. Each line taken off and plugged with 10psi pushed into them.
No leak in exhaust. This is a well maintained vehicle.
-30 shrt term fuel trims only at idle. Drives fine everywhere else except for tip in as the ecu has pulled max fuel and well is now lean on tip in takes a few seconds for it respond. Idles perfect at 14.7-15.3 afr even at -30. Still something is amiss
Miss Marie from South Main Auto sent me here
Awesome, welcome Ryan!
Mike Becker, Senior Technical Instructor
Linked from Young Marie at SMA.
Ms Marie sent me Good Job
Hey Kerry, thanks!
Mike Becker, Senior Technical Instructor
My thought- it will indicate Rich. Thinking- exhaust gas has very little oxygen, so the air into the engine will have Less than normal in And out when exhaust is added to the intake.
I'm a hobbyist, my own mech and Always learning. In lew of a smoke machine & tester I add trace refrigerant and use my leak checker! Bwaa haa haa!
I think the same concerning the EGR question.
A bar setting educational class as usual, Thanks a lot.
Thank you!
Mike Becker, Senior Technical Services Instructor
B its stuck open getting fumes from gas tank
Dear sir very good demonstration thank a lot.
Thanks Zwe Marn!
Mike Becker, Senior Instructor
Hello Mike,
I keep looking for a notice from wells tech about the next class, I have missed some perhaps, I don't know. I have trouble navigating the tech wells website, looking for love classes.
Respectfully,
AG
Hey Alex, I have not published anything yet on when the next class will be. That being said, it will be on Sept 7th at 11 am central time. Thanks!
Mike Becker, Technical Services Instructor
Can this be pcm ecm
Sure, the PCM could the culprit in many different diags...but I wouldn't jump to that conclusion. Maybe take this thing in somewhere?
Mike Becker, Senior Technical Instructor
Miss Marie from SMA sent me over.
Hey Bill, welcome!
Mike Becker, Senior Technical Instructor
That was a GREAT demonstration with the E85 gas, especially with the blue coloring additive, but it didn't seem obvious why you were doing all those ethanol tests in the first place. The title of your video is "Fuel Trims-Testing & Diagnosing Rich and Lean Conditions", but you don't mention how ethanol impacts fuel trim. In a future video you may want to discuss that, along with the effects on fuel trim due to ambient temperature extremes, summer vs winter fuel blends, humidity, barometric pressure, variances in octane, etc. Keep in mind too that Trump is threatening to legalize E15 everywhere to gain brownie points in the cornbelt. If that happens, it's going to cause some trouble with older cars, especially older cars in disrepair, who's fuel trims are already close to the CEL limit.
Hey Jay, thanks for watching! If I remember right, the point of that part was to test for water/ethanol in the fuel when diagnosing rich/lean conditions. The goal wasn't to explain what happens when there's ethanol present, just that it's a test to perform when checking for it. I believe it was one or 2 classes prior to this one I went into explaining what happens with ethanol in fuel.
Mike Becker, Senior Technical Instructor
im am by far not a drinker, im a smoker, but i do know that alcohols the only thing that has "legs" and that glass u were talkin about thats supposed to b premium fuel definitely had some self sustaining legs, they werent huge but definitely there
i have 97 mustang needs 02 sencer should i just replace all 4
Choice is yours Terry. There are a lot of factors that lead up to that decision. Check out this video we did on O2 sensors. Should help in making your decision. ua-cam.com/video/wZc-zCr2QnE/v-deo.html
Mike Becker, Technical Services Instructor
Thank You, this as been an EXCELLENT video.
Thank you for watching Rudolph!
Mike Becker, Senior Technical Instructor
Lean code because it’ll allow more air into the intake after the Mass AirFlow.
Miss Maria sent me too! New sub
Sweet, welcome!
Mike Becker, Senior Technical Instructor
Those intake gaskets look poor quality ! Are they OEM?
Can't remember Joe. They worked though.
Mike Becker, Senior Technical Instructor
hey mike. i love your vids. seems like NGK does not give you the same amount of time to go into detail
Hey Darren, it's pretty free to take as much time as needed. I try to keep them down to around an hour and a half. Once you go much longer you really start losing people. It really all depends on the lesson though.
Mike Becker, Senior Technical Instructor
what makes o2 stick rich
Could be a bad O2 sensor.
Mike Becker, Senior Technical Instructor
The best videos out there. Thanks for teaching us all....
Thanks Mike! You've seen just about every video at this point, huh?!
Mike Becker, Senior Technical Instructor
@@GoTechTraining Trying to see all of them.. Cant get enough of the knowledge your giving out..
Sent by Miss Marie!
Sweet!
Mike Becker, Senior Technical Instructor
Eric, on the question from Fox Brenton asking you about acetylene. We need to be careful here, Remember acetylene EXPLODES at the presence of OIL. I had the experience of gas and carb cleaner exploding on me. Gas on my face and propane a few feet away when checking for leaks, needless to say gas is nastier (sudden long flame) than propane (sudden flash) I do not want to be there when acetylene explodes. Definitely NOT RECOMMENDED.
Great comment! Any sort of flammable gas should be used in extreme caution. Propane is the ideal choice for these situations.
Mike Becker, Senior Technical Instructor
It is the oxygen side of the oxy acetylene torch set up that reacts to the oils in an explosive way (petroleum based lubes). This is the same chemical reaction when those commercial jet blew up and crashed. It was hauling oxygen generators the had a compressor leak ( refrigerant oil was exposed to the pure oxygen casing an explosion. Granted-the acytlene is very farmable but lacks the explosive ability on its own but if you mix in the oxygen till you have a neutral flame and snuff it out the explosive /unstableness potential of the acetylene increases incredibly and will explode with the slightest exposure to excessive heat or a small spark . But if you were to expose that pure oxygen to oil that may be the first and last time that you will ever be able to try that experience again🪦
great vid mike one of the best on the net thanks for shareing
Hey Mason, thanks!!!
Mike Becker, Senior Technical Instructor
Hell mike,
The intake manifold is a fix however I never reported that the car is experiencing hard starting, after a few cranks it starts not like it did before. Is it fuel regulator and fuel filter non of which I can immediately see?
Hey Alex, sorry it took so long to get back to you. So, does this only happen after the car sits for a bit? Does this happen if you shut it off, and try to restart it right away, or does it need to sit for a few hours? It could be the check valve in the fuel pump assembly. The fuel pressure could be draining back out of the rail and causing your extended cranking time because the pump needs to refill the rail every time.
Mike Becker, Technical Services Instructor
Hello Mike,
Hard starting happens all the time yet I had forgotten to mention that I had replaced old injectors with new injectors. The old injectors worked fine car immediately started all the time until injectors were replace, so I remove new injectors and noticed the rubber seats were bigger then the originals seats at the base. the o rings on top all matched. Now the car starts right up instantly however the check engine light is back on and the diagnostic devise read code P0171 lean bank one.
The live data long term fuel trim reads 0.80; short term reads 00 or drops to -3 then up to zero on idle.
O2 sensor reads 0.40 to 0.300 to 0.600 to 0.800 on idle.
mass air flow sensor reads 235 on idle
sprayed vaccum hoses with water no reaction to idle.
I will have to read about the check valve apparently the fuel regulator ; check valve and filter are all in one unit inside the fuel tank.
The car runs well and has power, the check engine light is on when disconnecting the battery negative lead the check engine light is gone and the diagnostic reads no codes pending.
However while driving at high speeds for an hour the check light returns again.
This situation intrigues my curiosity.
Is this codes P0171 a false code making a reference to something else?
Are my new injectors defective or one of them. I listened to the injector with a stethoscope then sound very close in vibration.
Should i use a garden hose to flood the manifold with water to hear any changes in idle speeds?
It may not be the check valve yet it would be good to examine it with volt meter?
Again many thanks, I was surprise to receive your email response.
Respectfully,
Alexander Gonzalez.
Hey Alex, looks like we are back to a lean code. Which is just saying there is too much O2 going past our sensor. So, do we not have enough fuel? Do we have too much air? I would not advise flooding the engine with a hose. I would much rather use propane or something like that to look for a vacuum leak. I can't remember, is the MAF new, or cleaned? That may be something to look at.
Mike Becker, Technical Services Instructor
Hello Mike,
reporting that I have used the propane gas and brake fluid upon starting engine from cold to warm just before it heats to high temperature, so far no systems of a leak. Check all the hoses, they seem to be snug tight. I suspect the brake cylinder vac um, only because when braking the pedal pressure weakened, ti happened once. I also suspect the posit crank case valve, it has not been cleaned out in 2years. The car runs well, i have disconnect the battery negative cable, 5 mins to make check engine light disappear after 8 days of high speed driving the check engine light come back on, its just amazing. This Makes me believe the the code P0171 LEAN CONDITION IS FALSE OR A REFERRED CODE TO SOMETHING ELSE HAPPENING or its just a faulty diagnostic computer from harbor freight, that is defective, who knows? this check engine light came back when I had taking out the new fuel injector to re-use old injectors, could be a cracked injector or poor rubber seal rings?
Respectfully,
Alex G.
ps eric o sent me what no good stuff? dontdaton!!!! hard for me4 im old you young kids are teaching old dog new tricks,keepn up the good work. thanks.
47:10 chunk missing,another chunk missing... bad material, the money light on, and people pay good money for this;
Also, you have to make absolutely sure that those "blue" rings stay well captioned in their nests when you assemble the whole shibang,you can't see them as you lower the manifold;
Yeh, you have to be super careful with them, they like to move around a bunch.
Mike Becker, Senior Technical Instructor
Marie sent me love your videos
Thanks Orville58!
Mike Becker, Senior Technical Instructor
necesitamos otro video en espanol me ha sido de mucha ayuda gracias por sus ensenanzas
Hola Celerino, Estamos haciendo esta misma clase en español LIVE el miércoles, 19 de abril a las 11am y 2pm hora central. Espero que te veamos allí.
Mike Becker, Technical Services Instructor
hi what scan tool u using?
Hey TC Auto, in this class I was using the Snap On Verus. Thanks for watching!
Mike Becker, Senior Technical Instructor
Pour a Fosters stubbie in the tank for an extra 20KWs!.Ha Ha. In Australia it was a Holden Monaro by the way.
Gotta get that extra power any way you can right? Ahhh a Monaro. I knew Holden made it, just couldn't remember the model name. Thanks tecnaman!
Mike Becker, Technical Services Instructor
P0101 fuel sys #1 clad cat load % 27.8 coolant 106 st ftrm1 % -22,7 Ltd ftrm1 % -10.9 map hg 19.2 ansley tps 13.7 frezz frame please help
Tyler, am I reading that right...-22% on STFT? That means the cars running rich, not lean!
Mike Becker, Senior Technical Instructor
do not understand why you had a lean condition on banks 1 and 2 when it was only bank 2
Tech B is right because when egr is stuck oxygen percentage detected by oxygen sensor is Comparatively high
But EGR is not oxygen, it's inert. So what does that do to our oxygen content? And what do you mean by it reading high? Like high voltage?
Mike Becker, Technical Services Instructor
Hello from utah miss Marie sent me
Hey Juan, Welcome!
Mike Becker, Senior Technical Instructor
Ya that's what code reader saved
It runs great in park but put in gear and it sputters