This is one of the things we always have to weight in the shop. How many hours, or how much further testing should we do, vs a fairly inexpensive part to test. Always a balance and what matters most is understanding the systems and when to do this type of diagnosis. Great work as always.
Love living in the day and times of our internet technology especially being able to watch you teach me how to PROPERLY troubleshoot and repair vehicles - if I learn half of what you KNOW and Teach - I will be a good tech 🙂 - That being said , you are inspiring and I want to be just as good as you - not just half as good 😏 . The reality of it is though - I DO recognize that the knowledge you possess and teach Is many years of experience 👍 SO being 60 years old myself - and a DIY mechanic ( generally) I GREATLY APPRECIATE YOU and your UA-cam video’s ✌️
I love the pre-inspection. I pull a code and look under the hood. This is the perfect time to fix oblivious damage. I get cars with partially installed air tubes or bad rodent damage and diag time goes down drastically. This technique is good for seeing the types of systems the car is using. ECT... Sometimes they will have a repair free by the dealer tsb or bulletin. You get burned and then you start to look first before you cross that street. Lol I love what this channel has to offer a technician who wants to better themselves.
48:10 Absolutely! Once I have determined sensor ground is intact, I always use sensor grounds as reference when scoping. I love the independent channel grounds of the Pico 4425 for this reason and cringe when I see people lumping all those grounds together on battery negative. Maybe they do it because Bernie said it so many times? But with a common ground scope, that's all you can do. While peak detect on snap-on can be useful in ensuring fast signals are not missed on a long timebase, it can lead you into seeing problems that aren't there - you're probably seeing the radiated signals from secondary ignition under load, which will be filtered out by the ECM.
It'd be nice if we could somehow put together a known good MAF reference table everybody could contribute to. Year, make, model, engine, intake air temp, idle rpm, coolant temp, and mass airflow amount. I think it'd be especially helpful on the smaller engines and forced induction stuff. I know I've seen on some of Bernie's videos where they have a VE database built into their diagnostic system on vehicles they've collected the data on but it'd be nice if we had just a general reference at idle for everybody to look at.
I made an Excel document to calculate G/Sec when I worked at Identifix Asian Dept. docs.google.com/spreadsheets/d/1ZF0zIhZW6VPhw7S-D41zm_uRoLi2kTwJAlP_iiOoSm8/edit?usp=sharing Let me know if the link doesn't work.
Thanks so much Paul and Danner for another great video. Lots of good tips and it is great when we get to see you go through cases like this that might not make sense at first but through knowledge of basics you show us how to interpret the data and come to a solid conclusion and fix. Merry Christmas to you and your families and I wish you a wonderful holiday. Thanks so much.
5 mins in and I’m thinking it’s maf! I’m thinking this because I already had a similar issue, but it was over fueling. No codes in the system but the maf reading was around 4.9v. Cold , sensor was clean! I took one from another vehicle and it solved the issue. We had this car sitting for a month with one of the techs just throwing parts at it! I had a look at the data and notice the maf reading were not as per the reference values. Sometimes it pays to read your shop manuals when looking for no code faults just to see if anything jumps out at you. I was lucky to find this, I think the other techs frustration made him lose his thought train.
Another great video and teaching moment! I totally agree with your call on the MAF. All of your data was pretty much pointing in that direction and then once seeing that it was an aftermarket sensor, I was convinced that was going to be your problem. Great call and you are definitely not a parts changer! Sometimes we have to weigh out the cost of a part versus another hour of diag just to end up back at the same place. Well done Danner duo! 😅
Can’t say enough about the things you SMA And Pine Hollow have given to me this year. It’s Christmas everyday from you guys. Thank You so much!! And Stay warm Merry Christmas to you all and your familys
Really good video! Anyone ever seen this? Well maintained 2007 Camry had a p0101 code & system rich 5 months ago. Total trims around - 40. Pwrs/Grounds good, no vac leaks, pcv good. Replaced MAF with Denso made in Japan & that fixed it. Best fuel trims I'd ever seen on my wife's car, around -2 total trim. I keep a bluetooth scanner connected each time I drive her car so I monitor trims multiple times per week. They stayed GREAT. No codes, no issues. Ran like new. 5 months later, same codes re-appeared while my wife was driving car. When she got home, I hooked up my scanner to check it out and the fuel trims were correcting.... as if the problem was fixed.... but I didn't fix anything, didn't touch anything. Long trim was -20, Short was +20, "correcting" for whatever the problem was all by itself. I've been testing everthing I can think of, and driving the car daily for 5 days and the problem is gone again. The only difference I see is, now total trim is a bit higher.... around 9 under load, around 5 at idle. Any experience or guidance would be appreciated. I'm a home DIY-ing Dad, but a long time student of ScannerDanner's book, premium, and youtube content. Paul (& James) have taught me a lot so I would probably describe my skill level as high on understanding and knowledge of what ScannerDanner teaches, but low on actual experience working on a lot of cars, as the only issues I ever get to work on are my family's cars, which I take care of so they don't normally have many issues. Thanks for any suggestions.
You'll need to catch that problem when it is happening. It's pretty difficult to make a call when the system is correcting and the problem isn't currently there. Thank you! Pretty awesome that you understand what the counter fuel trim numbers mean!
Hi Paul, I'm an electrician, with electronics repairer knowledge. I don't have access to good scanner. I have simple OBD scanner. This scanner allows to do some advance programming on GM vehicles. ABC blead, Crank Position sensor, Transmission diagnostics and more. I have 2002 Chevy Avalanche 1500. Truck was sitting with blown engine sins 2006. I replaced engine (I drove the donor on parking lot). I replaced the tranny with remanufactured one (old tranny has antifreeze in side). Take truck for inspection. No pass. No check engine light. Technician sad that truck need MAF. No check engine light. It can be seen on scanner. Trouble shooting steps: 1. Cleaned MAF. Code pop up after 15-20 min drive. 2. Replaced MAF from good running truck. Code pop up after 15-20 min drive. 3. Stop by other local shop for diagnostics. The technician replaced MAF with new AC Delco MAF. ($150 MAF and $350 labor). Code pop up after 15-20 min drive. Technician sad tis is wiring problems. 4. I check continuity from MAF connector to PCM with tester and with test light (under load). Ho wire damage. Good ground. 5. Check PCM connector, MAF connector, check wiring - move the harness with engine running. Sprayed water on intake manifold, throttle body, No effect. 6. Replaced PCV (PCV was bad). No effect. 7. Replaced AC Delco MAF with new AC Delco MAF. Code pop up after 15-20 min drive. 8. There 12v on Pink and Black wire. 4.5v on Yellow wire. (this 5.3l has cable TB). I "jerk" the throttle - voltage dropped from 4.5v to 4.2-4.12v on Yellow wire. 8. I checked O2 sensors (they new Denso). I connect OBD dangle and see graphs on my phone. All 4- O2 sensors acting healthy. No misfire. 9. I reassessed PCM. Goes throw the learning prosses. Code pop up after 20 min drive. Now I run out of options. Is there any suggestions? Or any good diagnosis you can recommend? I'm on NY.
I work for suzuki in New Zealand the maf sensors on these older sx4 with the jb20 engines and the suzuki swifts with the m13 m15 and m16 engines are very common to crap out
Thank you Paul for another great video where persistence and data clearly showed the fault, I take this opportunity to wish you and your family Merry Christmas wishing you the best
Since this was an engine out rebuild look for rags stuck in intake, had one with a blue towel stuck against MAF screen causing rich condition due to higher air velocity thru MAF from restriction. I saw you pulling airbox and was just waiting to see this.
I watched your fuel trim videos many years ago and learnt an awful lot from it . Use that info every time I have a running fault on a petrol engine …. thanks for the $$$’s sir. 👏👍😀
Good thing I own a 2008 sx4 all wheel drive . Good to bank this one into my suzuki vault of repair data. Thank you. Merry Christmas to you and your family.
Rich and lean codes are a pain!! But you always mail them… thank you for another great video, I learned so much just watching your videos!!! Merry Christmas to you and your family and a Happy New Year!!!
I want say that's great thing you added it with humble mechanic on tool box build. Merry Christmas and God bless. Hopefully next year our company and help with it.
Great video for my class, i am like you, 3rd year automotive instructor at Southern alberta institute of technology in Alberta Canada, I always teach the importance of understanding Fuel Trims, Thanks Paul FERAS
On cars with vacuum brake booster system, when I’m going to make the trims go to lean from the driver seat on engine idle I just push the brake pedal few times and that does it for me. And yes it depends on what I’m trying to chase and which PIDs I’m trying to look at. Merry Christmas everybody
Paul hope you guys have a good Christmas and as always many many thanks for educating us. Caleb thanks for helping your dad by editing videos and posting it for all of us.
This reminds me of the time we had a car and they put a federal emissions engine in a California car the intakes were a bit different which gave us a slight idle problem and code.
Great video! I have a 2002 Volvo S60 non-turbo with P0172. It has a new fuel pump, fuel filter, injectors, upstream O2 sensor and an Evap purge solenoid. MAF and throttle body have been cleaned. It has a rough idle on start up also when it reaches operating temperature. When I pull the connection to the MAF sensor, it idles better and response better when engine is rev up. Does this mean my MAF sensor is bad. It is the original MAF sensor with 204000 miles.
When I was looking at the scan tool data I noticed you had key on engine off you hadn’t started it yet. It showed 1. point something grams at the Maf. I know Toyota had a TSP back and I think 2005 or 2006. It would help if you look at grams per second key on engine off and if it was outside of that specific number the MAF was bad.
Seeing the scanner actually display an equivalence ratio, that's actually the most accurate output from the wideband sensor. EQ ratio essentially is lambda, so for example 0.95 lambda (13.965:1 AFR) in open loop means a -5% trim will bring it back to stoich mixture. And vice versa, if it's at 1.05 lambda (15.435:1 AFR), it will need a +5% trim to get it back to stoich.
This was a extremely helpful video, one thing I was wondering was since you were seeing high calculated load percentage, and setting a rich code, can it be the opposite as well, where there are low calculated load numbers and setting a lean code? With no vacuum leaks. Also being a skewed MAF? I havent had time to read through all the other comments for this video, so not sure if that question may have been answered.
I have an 04 GMc Jimmy 4.3L. I have a p0101 code with p0172/175 Banks 1&2 rich. My MAF is new, reading 9-10g/s. Up stream O2 fluctuate between .8 and .1 as they suppose too. My Long fuel trims -25 as well as short fuel trims. I replaced the MAF and Spider injection. With MAF unplugged, it shows the default MAG 1.62 G/S and fuel trims are close to 0. Not sure what else can cause this.
all suzukis after 2005 show code p0130 for the o2 sensor and rarely show a code for lean or rich mixture. whenever we have such a code we always look at the fuel trims to tell us if the o2 sensor is at fault or not. at 7.30 in your video you do the test by pressing the gas and leaving it, there the sensor first goes lean and then rich until it goes to o ma. but the o2 sensor is fine
So i have heard of Maf Initialization being perhaps required for Mafs for sprinters it seems a hotly debated subject in sprinter forums with no conclusive yes or no .I have 2006 t1n replaced maf oem and it wont run unless Maf unplugged still , turbo wont kick on etc ,after watching some of your incredibly interesting lectures i tested voltage ,ground ,sensor ground and sensor signal all good but it still fires and dies ,then i heard about initialization perhaps being nescesary , vehicle is getting 2068-4 Maf faulty on/off ratio of reference signal is outside permissible range , i wonder if Initialization would adjust this and does it need to be a mercedes dealership to accomplish this , am glued to your inspiring lectures, thank you, if i was a little younger .....
I seen the CRC can come out and I'm like ummm that stuff ain't flammable........ know that becuase I did the same thing just a few weeks ago😂. Great video as always.
@Scannerdanner - Paul, great video as always. The only thing I am a little lost at is why the wideband sensor showed 0 ma or stoichiometry yet the fuel trims were so negative.I know the calculated load percentage was high, but would have thought wideband would not have stayed at 0 ma. throughout all this. Thank You.
@ScannerDanner- this car appeared to be running rich with very negative fuel trims , but the wideband 02 sensor never moved from 0 ma of current- stoichiometric - the only pid out of whack was a high calculated load percentage. Just seems weird the wideband never moved from 0 ma of current. Thank you Paul.
Hey, at 44:30, the downstream O2 sensor is sitting at around 0.8 V. Is this cause for concern? From what I can tell, I don't think its an issue because you still have good fuel trims. Is this a bad sensor? Is this a normal reading? If anybody has any insight I would really appreciate it! From
Less then a 3 liter engine you say cant use the rule of thumb with g/s based on liter of engine. I understand that as I use it. But question is will a smaller
Crazy as it might sound, the gram/sec rule being less accurate under 3L displacement kind of reminds of Asimov's Foundation series, wherein a group of scientists use a mathematical formula to predict human group reactions. Bigger the group, the more accurate the prediction. Small groups being nearly impossible to chart. Closer you get to the wire, as it were, the greater the uncertainty, simply because smaller numbers are tougher to average with any accuracy. Same deal here.
Great video Danner boys as always.Call me a parts snob but OEM all the way been there to many times with after market parts especially with Todays Technology.Everyone have a Merry Christmas and a safe and Happy New year.God Bless.
Why do some cars not show you the upstream o2 voltage?.. But instead show you the current, i never understood that and always have a hard time diagnosing because of that
Dear Paul, hello! I'm fighting now with Subaru. Engine was swapped from 1.5 A/T to 2.0 M/T, there was a lot of mess and misconnected wires. Looks like i've fixed wiring problem. But i still cant fix what is wrong with MAF. I have a new original MAF sensor. And i have around 4 volts full throttle. But my grams per second readings are 12 grams at idle, and 400 grams full throttle driving test, average 2.0 atmospheric engine. I've thought ECU was from some turbo subaru, or was re flashed. So i've bought a used ECU for this engine, and, i see the same readings. FUnny that my injection pulse at idle is 2.8 ms, it doesn't look like 3 or 4 times more. And, no backfire in exhaust. I can start engine warm, if i've had a 3-4 time more fuel, i would have drowned engine with fuel and never could start it warm. Also there is Bosch 5 wire LSU 4.2AF sensor. Reference 2.55 volts wire was swapped with pumpig current calibration wire, so my AFR was constantly 0.69 without any chance to go rich,Only lean. After i've fixed wiring problem, i have 1.0 AFR until my front AF sensor warms up, then i get -20% short term instantly, and my rear O2 sensor goes lean, low voltage.SO i assume wrong readings for my front AF sensor. But. also i have now 35 kPA at idle, it is higher than it should be. Maybe i have a good AF sensor now, but i have plugged exhaust? or Valves are not sealing combustion chamber properly? Or my AF sensor after thousands KM o fwrong connection damaged?Is that possible?
Let's move this to my forum www.scannerdanner.com it is free to join and we can try to help you there. When it comes to engine swaps, especially to a different size completely, things get complicated and I can't do this here. Too much research to do by myself to help you. Thanks! Hope to see you there.
Just a thought: if there's a frequency analyzer on the scan tool you might find out that there's a specific frequency responsible for the "hash" on the MAF signal. This does not look like random noise but specific signal pulses. Maybe the firing of injectors is responsible for the hash.
This hash is really everywhere in a car. If I'd have used sensor ground you wouldn't have seen it. But the main reason you did was with peak detect turn on, on my scope, it is sampling that screen 6 million times. If I farted you'd see it with that sample rate lol
On my Toyota 2.4L, the g/s at idle is right around 2.2-2.8. In my case, the g/s is very close to displacement at idle. I don't like my Total fuel trims though, edging up toward +10% at idle. I'll inject a flammable in the intake and see which way the trims go. I had a very brief stumble at start that cleared up when the weather got colder. Thanks for the videos, lots to learn, much to apply.
@@ScannerDanner Thank you, SD. It could have a vacuum leak at idle and then the problem is masked while driving? I took my scan data and used max RPM and MAF, IAT and atmospheric pressure and calculated volumetric efficiency and got 110% VE. I blame the fantastic videos you put out loaded with information. I'm doomed I tell ya.
Hey Paul,, great flick as always. I have a question for you. At around 27. 45 you mentioned "let's go to the graphing meter" When do you want to use the scope vs the graphing meter and vice-versa?
This wasn't a great example of when to switch to the graphing meter. I just wanted to see what it looked like with a longer time base, without worrying about the scope sample rate (peak detect) I'd say in short, I don't use the graphing meter very often these days unless I'm looking for a glitch or drop out on a time base longer than 5 seconds. Or if I want to graph a voltage trace that is a constant signal that shouldn't change and I'm looking for a glitch/drop out I'd definitely use the GMM for that
@@ScannerDanner thanks you very much for taking the time to answer in details, it is much appreciated. I'll add that to my book of tricks. Happy holidays to the Danner family and long live this channel.
Question I got a Buick 3.8 supercharged Buick park ave and I have a p0172 I checked the term #s and seem to be ok. What can else can I look for? Thanx ..appreciate any tips
Sir in this after replace maf o2 sensor2 is going up700mv .my thinking that it reading should 450 mv.750 mv means that's system is little bet rich but fuel terms are normal .plz explain
Im randomly getting codes p2198, p2098. Also same for the other bank (2196,2096). on a 2010 Audi S5 V8. I do also get P0141 sometimes. I get LTFT -8 to -17 at most for both banks usually a bit higher for B1. Replaced OEM injectors, carbon clean, low pressure fuel pump and filter, low and high fuel pressure sensors. Plugs, coils, HPFP and pre cats O2 sensors replaced about 55k kms on it. MAF is original, I tried another one with same results. I even check the Evap purge valve. Downstream O2’s seems to be working fine, both reading about .60sh to 70sh. I removed them and cleaned. What else I could check? I want to to a flags tune on the ECU. 🤷♂️btw, cars runs great with lots of power it’s just those codes coming once in a while. Sometimes if I do startup and rigth away drive only trigger p0141 heated exhaust gas.
Your first mistake was replacing all these parts based on these codes without doing any testing. Now you've added additional variables (bad new parts) to the mix. Define all the codes please.
I have a 20008 grand marquis it idels high until I put it a gear then It doesn't wanna accelerate after a little while I've changed spark plugs Coil packs cleaned throttle body kinda of Lost atp do you think it's my TPS ) throttle position sensor or what would you think the problem is ? Anybody!?
My subaru forester 2.5 xt is overfeuling black smoke only on normal operating temperature start up not doing it on cold start its doing it for about 5 sec then smoke disappears do yoz think its maf?
Hello ScannerDanner, I need your help and advice!! I'm a diy'r, but with above average mechanical skills and general knowhow...lol. I'm looking for a pro-grade scanner, but want to save some $$$. I've allotted $500 for a scanner, but I want to ensure I have full...or near full diag capabilities with respect to being bi-directional, and the ability to scan and reset systems. Which brand would you recommend and why?
The topdon phoenix Lite, hands down. But you'll be spending around $900 for it. Though topdon is now offering a less expensive unit that is not bluetooth but would be tethered and it goes for around $500 but if don't know if it's "full function" like the phoenix
My 2009 Honda Accord Stalled 5 years ago After I Drove Through High Waters But After A Few Tries It Started Again But With The Engine Light 5 Years Ago And Was Told The Catalytic Converter Is Bad, That’s The Code That Comes Up. As I’m Driving Sometimes Exhaust Smells Permeate The Interior Which Smell Like Rotten Eggs. Also Somehow I’ve Managed To Pass DMV Inspection 4 Years Straight With A Check Engine Light & Bad Catalytic Converter. What’s crazy is that this year I failed the DMV EMISSION TEST 4x and then I went to a shop and asked them to clear the codes and prayed and when they checked again at the DMV it passed 😂. This year they were strict but prior years they weren’t even checking! The dealership says I have Low Compression On The Number 4 Cylinder & P0420 & P0304. They say the engine was at 60psi. They performed the diagnostic in July. I heard Cataclean cleans the catalytic converter. I saw it on Amazon. What do you think? Is That Bad Catalytic Converter Endangering My Life?
Fix your misfire first before ever worrying about CAT codes. Also the rotten egg smell is not from a cat that's failing, it's from raw fuel being dumped into the cat. Most likely from the low compression cylinder.
@priestlygarments4004 hard to say, it certainly isn't healthy for that engine or the cats to continue to drive it with a constant misfire. It is a constant misfire right? At 60 psi of compression it has to be. I'd recommend unplugging the injector for that cylinder.
@@ScannerDanner Oh wow! What about my health? Should I be worried of carbon monoxide? Cause Honda is asking for 6,000 to put a used engine 2,000 for a used cat. I don’t even have those funds at the moment. I paid them to diagnose and all the lady said is that it’s not worth repairing to just buy a new car 🤦🏽♂️. I regret driving through that water trying to pick up an Uber rider. 😂 The car moves very well bro just the TPMS LIGHT is on and the engine light is solid. They said the TPMS sensor could be dead because the tires are perfect. Just those lights are on! Everything else is solid. I failed the DMV emissions test so I just had the dealership clear the codes temporarily and it passed.
Thank you for these very instructive videos. I'm a newcomer on your channel, you are a great teacher, and I think this is what I was looking for! What about fuel trim diagnostic strategies for cars that have MAP Sensor instead of MAF Sensor?
It's no different, but vacuum leaks certainly effect them differently. I have some classes on that. Maybe even one here on UA-cam. Check my chapter 1 playlist. I'd be there if I have it.
@@ScannerDanner Thank you! I have checked out the chapter one playlist on UA-cam and unfortunately I think there isn't. But, please, what do you mean by vacuum leaks affect them differently.
@@ovidiumonoranu367 too long to type out, as it is very complex. I have lectures on this one my website if you can't find what your looking for here. This one in particular www.scannerdanner.com/scannerdanner-premium-chapters/chapter-1-universal-testing-methods/chapter-1-universal-testing-methods-full/202-chapter-1-universal-testing-methods-pages-9-13.html
I find it interesting that a doctor can practice but the general public expects techs to get it right the vary first time. Im mean look how incredibly complex these systems are.
Thanks for your video but i can' t focus you didn' t say your grandson is fine??? Your best videos with your brother he is a great man .merry christmas to you and your family.lg.
Suzuki that’s your first problem. Surprised the snap on had it since they’re not made anymore. I always watch diagnose Dan basically widebands are reverse of narrow band
Hey over the years I’ve been going through all your videos, including premium, wondering; how this same scenario would play out on a speed density engine with an aftermarket map sensor? I would love it if you could talk more about that style. I have a Subaru I love that I just can’t give up on, but have struggled to learn enough information to identify the problem.
Hey I got a question this may be a little bit off subject but since we're talking about oxygen sensors on foreign cars like Hyundai's Hondas does the downstream oxygen sensor play a row in the fuel trims I have noticed several times that the downstream oxygen sensors fuel trims will be 99% and we'll never change from thatBut if you look at the downstream oxygen sensors on OBD2 or under Hyundai you will notice that they are working but the fuel trims r still stuck at 99% a lot of times I've never really wrapped my head around this
when you see downstream fuel trim at 99%, this is a data parameter that is not being use. Also, I have never, not once, seen downstream fuel trim being used with a narrow band upstream O2. Only some systems with wideband upstreams will they also use a downstream fuel trim strategy for minor corrections. In my chapter 4 and 5 playlist I have a case study on one with downstream fuel trim control. Thanks!
@@ScannerDanner thanks for the reply I really appreciate it I would love to get your book just been a little short on cash here lately I believe the car does have wideband upstreams anyways like I said thank you sir appreciate the info
@diamondstateautodiagnostic5250 oh no man I wasn't suggesting you go and buy my book I have playlists right here on UA-cam that correspond to the chapters in my book but that's all, you don't need the book to benefit from this. here's the playlist I was talking about ua-cam.com/play/PLD2809EEC7BAAF989.html
thank you sir I really appreciate that one of these days I really would like to buy your book and join your premium Channel I love watching u videos I don't even watch TV anymore I just come home and watch your videos LOL maybe one of these days I can order a book from you I'd love to have a signed copy LOL
@@diamondstateautodiagnostic5250 I can do that 😉, just sent a signed one to the Uk Email me at support@scannerdanner.com when you want one. Thanks again!
Good find. I agree with MAF’s are the hardest to call or take a gamble with. I’ve got lucky a few times and also not so lucky. But on another subject. Dealing with a 03 Ram that has a single misfire during decel. Full tune-up has already been done due to carbon tracking on plug. Injector also replaced to see if that was an issue. Idle and normal driving is fine. Any ideas on what to look at or test? Thanks if you can shed some light.
@@ScannerDanner figured it out. Used a pressure transducer and saw something going on with the exhaust side. Put a scope in the cylinder and saw the valve had worn into the head and rounded the seat.
So you didn't make the MAF call based on the lab scope signal, you based your call on the high engine load percentage? The old and "new" MAF sensor signals look the same, or did I miss something?
@@ScannerDanner So, if MAF is used by the ECU to calculate engine load, why didn't we see a significant difference in wave form? Or, did you need to get more granular on the time base to see it?
@superk4562 we did in the grams per second reading at idle and also the stability of the signal. I can't remember the numbers offhand but I think the old MAF was jumping up to 4 grams per sec at idle and it was very erratic
@@ScannerDanner This is really cool! I've been troubleshooting a 1999 Ford F150, 5.4L 270K miles on it with a brand new long block. I reused some components I probably shouldn't have. I found a very small leak in the EGR valve and I replaced it. Fuel trims were 13 and 12, bank 1 and 2 respectively. I looked at the MAF, it appeared to be working but it was only reporting 4.9 g/s at idle. I installed a new MAF sensor, and g/s went to 6.2. As soon as I installed the new sensor, short-term fuel trims went negative, and started pulling the long-term fuel trim down. Now, the fuel trims are near zero, but I still can't get rid of the surge at idle; weird thing is the idle will only surge in Park or neutral. Any ideas? I've already smoke tested in the intake ... no leaks. IAC is new too.
Happy holidays sir ! I wanted to ask on how you can find out right away on whethere high voltage on the scanner graph means rich or does it mean lean on this particular vehicle, and does it change from vehicle to vehicle ? Thank you so much for all your videos
I got confused because i wasnt paying attention to where on the video the b1s1 pid is displaying amperage, too where the other b1s2 pid is displaying voltage ! That's why on one the graph goes up and the other goes down on deceleration test
It's a wideband so they don't move the same way. When I used global data you could see the rich lean swings. I think I showed that in this video? Thanks!
Don't forget to check the description for time stamps and links to the other videos mentioned. Thank you everyone and Merry Christmas!
Merry Christmas to you and yours brother
Merry Christmas to the Danner family.
MERY CHRISTMAS MY FRIEND
Merry Christmas and a Happy New Year!
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4:57 you can rapidly stab the brake pedal to force a lean condition also. Eric o from sma taught me that trick
This is one of the things we always have to weight in the shop. How many hours, or how much further testing should we do, vs a fairly inexpensive part to test. Always a balance and what matters most is understanding the systems and when to do this type of diagnosis.
Great work as always.
Love living in the day and times of our internet technology especially being able to watch you teach me how to PROPERLY troubleshoot and repair vehicles - if I learn half of what you KNOW and Teach - I will be a good tech 🙂 - That being said , you are inspiring and I want to be just as good as you - not just half as good 😏 . The reality of it is though - I DO recognize that the knowledge you possess and teach Is many years of experience 👍 SO being 60 years old myself - and a DIY mechanic ( generally) I GREATLY APPRECIATE YOU and your UA-cam video’s ✌️
Thank you so much!
I love the pre-inspection. I pull a code and look under the hood. This is the perfect time to fix oblivious damage. I get cars with partially installed air tubes or bad rodent damage and diag time goes down drastically. This technique is good for seeing the types of systems the car is using. ECT... Sometimes they will have a repair free by the dealer tsb or bulletin. You get burned and then you start to look first before you cross that street. Lol I love what this channel has to offer a technician who wants to better themselves.
Thank you so much!
48:10 Absolutely!
Once I have determined sensor ground is intact, I always use sensor grounds as reference when scoping.
I love the independent channel grounds of the Pico 4425 for this reason and cringe when I see people lumping all those grounds together on battery negative.
Maybe they do it because Bernie said it so many times? But with a common ground scope, that's all you can do.
While peak detect on snap-on can be useful in ensuring fast signals are not missed on a long timebase, it can lead you into seeing problems that aren't there - you're probably seeing the radiated signals from secondary ignition under load, which will be filtered out by the ECM.
Cheers you guys I need to learn more on fuel trims at 70 love it.
It'd be nice if we could somehow put together a known good MAF reference table everybody could contribute to. Year, make, model, engine, intake air temp, idle rpm, coolant temp, and mass airflow amount. I think it'd be especially helpful on the smaller engines and forced induction stuff. I know I've seen on some of Bernie's videos where they have a VE database built into their diagnostic system on vehicles they've collected the data on but it'd be nice if we had just a general reference at idle for everybody to look at.
Service information has specifications for engine performance parameters.
@@Turbotomass Not for everything, also a lot of DIY guys aren't going to have access to service info
I made an Excel document to calculate G/Sec when I worked at Identifix Asian Dept.
docs.google.com/spreadsheets/d/1ZF0zIhZW6VPhw7S-D41zm_uRoLi2kTwJAlP_iiOoSm8/edit?usp=sharing
Let me know if the link doesn't work.
@@ToddErickson365 hey man I requested access with the link you posted
Thanks so much Paul and Danner for another great video. Lots of good tips and it is great when we get to see you go through cases like this that might not make sense at first but through knowledge of basics you show us how to interpret the data and come to a solid conclusion and fix. Merry Christmas to you
and your families and I wish you a wonderful holiday. Thanks so much.
5 mins in and I’m thinking it’s maf! I’m thinking this because I already had a similar issue, but it was over fueling. No codes in the system but the maf reading was around 4.9v. Cold , sensor was clean! I took one from another vehicle and it solved the issue. We had this car sitting for a month with one of the techs just throwing parts at it! I had a look at the data and notice the maf reading were not as per the reference values. Sometimes it pays to read your shop manuals when looking for no code faults just to see if anything jumps out at you. I was lucky to find this, I think the other techs frustration made him lose his thought train.
Another great video and teaching moment! I totally agree with your call on the MAF. All of your data was pretty much pointing in that direction and then once seeing that it was an aftermarket sensor, I was convinced that was going to be your problem. Great call and you are definitely not a parts changer! Sometimes we have to weigh out the cost of a part versus another hour of diag just to end up back at the same place. Well done Danner duo! 😅
Can’t say enough about the things you SMA And Pine Hollow have given to me this year.
It’s Christmas everyday from you guys. Thank You so much!!
And Stay warm
Merry Christmas to you all and your familys
Both great channels and good friends. Thanks so much!
Really good video! Anyone ever seen this? Well maintained 2007 Camry had a p0101 code & system rich 5 months ago. Total trims around - 40. Pwrs/Grounds good, no vac leaks, pcv good. Replaced MAF with Denso made in Japan & that fixed it. Best fuel trims I'd ever seen on my wife's car, around -2 total trim. I keep a bluetooth scanner connected each time I drive her car so I monitor trims multiple times per week. They stayed GREAT. No codes, no issues. Ran like new. 5 months later, same codes re-appeared while my wife was driving car. When she got home, I hooked up my scanner to check it out and the fuel trims were correcting.... as if the problem was fixed.... but I didn't fix anything, didn't touch anything. Long trim was -20, Short was +20, "correcting" for whatever the problem was all by itself. I've been testing everthing I can think of, and driving the car daily for 5 days and the problem is gone again. The only difference I see is, now total trim is a bit higher.... around 9 under load, around 5 at idle.
Any experience or guidance would be appreciated. I'm a home DIY-ing Dad, but a long time student of ScannerDanner's book, premium, and youtube content. Paul (& James) have taught me a lot so I would probably describe my skill level as high on understanding and knowledge of what ScannerDanner teaches, but low on actual experience working on a lot of cars, as the only issues I ever get to work on are my family's cars, which I take care of so they don't normally have many issues.
Thanks for any suggestions.
You'll need to catch that problem when it is happening. It's pretty difficult to make a call when the system is correcting and the problem isn't currently there.
Thank you! Pretty awesome that you understand what the counter fuel trim numbers mean!
Thanks. You're an excellent teacher.
GBY All!🙏❤😊Thank you for bringing uncommon knowledge to the common people❤😊
Hi Paul,
I'm an electrician, with electronics repairer knowledge. I don't have access to good scanner. I have simple OBD scanner. This scanner allows to do some advance programming on GM vehicles. ABC blead, Crank Position sensor, Transmission diagnostics and more.
I have 2002 Chevy Avalanche 1500. Truck was sitting with blown engine sins 2006.
I replaced engine (I drove the donor on parking lot). I replaced the tranny with remanufactured one (old tranny has antifreeze in side). Take truck for inspection. No pass. No check engine light. Technician sad that truck need MAF. No check engine light. It can be seen on scanner.
Trouble shooting steps:
1. Cleaned MAF. Code pop up after 15-20 min drive.
2. Replaced MAF from good running truck. Code pop up after 15-20 min drive.
3. Stop by other local shop for diagnostics. The technician replaced MAF with new AC Delco MAF. ($150 MAF and $350 labor). Code pop up after 15-20 min drive. Technician sad tis is wiring problems.
4. I check continuity from MAF connector to PCM with tester and with test light (under load). Ho wire damage. Good ground.
5. Check PCM connector, MAF connector, check wiring - move the harness with engine running. Sprayed water on intake manifold, throttle body, No effect.
6. Replaced PCV (PCV was bad). No effect.
7. Replaced AC Delco MAF with new AC Delco MAF. Code pop up after 15-20 min drive.
8. There 12v on Pink and Black wire. 4.5v on Yellow wire. (this 5.3l has cable TB). I "jerk" the throttle - voltage dropped from 4.5v to 4.2-4.12v on Yellow wire.
8. I checked O2 sensors (they new Denso). I connect OBD dangle and see graphs on my phone. All 4- O2 sensors acting healthy. No misfire.
9. I reassessed PCM. Goes throw the learning prosses. Code pop up after 20 min drive.
Now I run out of options. Is there any suggestions?
Or any good diagnosis you can recommend? I'm on NY.
What code?
I work for suzuki in New Zealand the maf sensors on these older sx4 with the jb20 engines and the suzuki swifts with the m13 m15 and m16 engines are very common to crap out
Thank you Paul for another great video where persistence and data clearly showed the fault, I take this opportunity to wish you and your family Merry Christmas wishing you the best
Since this was an engine out rebuild look for rags stuck in intake, had one with a blue towel stuck against MAF screen causing rich condition due to higher air velocity thru MAF from restriction.
I saw you pulling airbox and was just waiting to see this.
Caleb great job filming and editing. Paul & Dan great job on being cool dudes and the service you provide.
Caleb is the man. Thank you! Merry Christmas
I watched your fuel trim videos many years ago and learnt an awful lot from it . Use that info every time I have a running fault on a petrol engine …. thanks for the $$$’s sir. 👏👍😀
Good thing I own a 2008 sx4 all wheel drive . Good to bank this one into my suzuki vault of repair data. Thank you. Merry Christmas to you and your family.
Rich and lean codes are a pain!! But you always mail them… thank you for another great video, I learned so much just watching your videos!!! Merry Christmas to you and your family and a Happy New Year!!!
Thank you and Merry Christmas to you too!
Would have been interesting to see the wave form with the sensor ground. Love your channel!
I want say that's great thing you added it with humble mechanic on tool box build. Merry Christmas and God bless. Hopefully next year our company and help with it.
Thanks Paul. Merry Christmas to you and family. Merry Christmas to the entire SD community.
Loved it. I'm going through the same thing on a Honda. Good seen you and your brother. may God bless you all and your family
Great video for my class, i am like you, 3rd year automotive instructor at Southern alberta institute of technology in Alberta Canada,
I always teach the importance of understanding Fuel Trims,
Thanks Paul
FERAS
Thank you!
On cars with vacuum brake booster system, when I’m going to make the trims go to lean from the driver seat on engine idle I just push the brake pedal few times and that does it for me. And yes it depends on what I’m trying to chase and which PIDs I’m trying to look at. Merry Christmas everybody
Paul hope you guys have a good Christmas and as always many many thanks for educating us. Caleb thanks for helping your dad by editing videos and posting it for all of us.
Blessed to have my son working with me. Thank you!
This reminds me of the time we had a car and they put a federal emissions engine in a California car the intakes were a bit different which gave us a slight idle problem and code.
Awesome description of the process to get to the final result. Nice work as always and thanks for posting the video man.
Thank you!
Great video! I have a 2002 Volvo S60 non-turbo with P0172. It has a new fuel pump, fuel filter, injectors, upstream O2 sensor and an Evap purge solenoid. MAF and throttle body have been cleaned. It has a rough idle on start up also when it reaches operating temperature. When I pull the connection to the MAF sensor, it idles better and response better when engine is rev up. Does this mean my MAF sensor is bad. It is the original MAF sensor with 204000 miles.
When I was looking at the scan tool data I noticed you had key on engine off you hadn’t started it yet. It showed 1. point something grams at the Maf. I know Toyota had a TSP back and I think 2005 or 2006. It would help if you look at grams per second key on engine off and if it was outside of that specific number the MAF was bad.
22:22 There you go! There's a bug in the system! lol
Stink bug for the win lol we actually have a video where that's what it was. Nice to hear from you Brian!
Merry Christmas to you and your family Paul. Another great video on fuel trims. Thanks.
Seeing the scanner actually display an equivalence ratio, that's actually the most accurate output from the wideband sensor. EQ ratio essentially is lambda, so for example 0.95 lambda (13.965:1 AFR) in open loop means a -5% trim will bring it back to stoich mixture. And vice versa, if it's at 1.05 lambda (15.435:1 AFR), it will need a +5% trim to get it back to stoich.
it's just another O2 data PID that can be false when there is a sensor malfunction
@@ScannerDanner I agree, but for this specific case the EQ ratio works better than the O2 mA. Great video otherwise!
Thanks Paul and a very Merry Christmas to you and the family !
This was a extremely helpful video, one thing I was wondering was since you were seeing high calculated load percentage, and setting a rich code, can it be the opposite as well, where there are low calculated load numbers and setting a lean code? With no vacuum leaks. Also being a skewed MAF? I havent had time to read through all the other comments for this video, so not sure if that question may have been answered.
I have an 04 GMc Jimmy 4.3L. I have a p0101 code with p0172/175 Banks 1&2 rich. My MAF is new, reading 9-10g/s. Up stream O2 fluctuate between .8 and .1 as they suppose too. My Long fuel trims -25 as well as short fuel trims. I replaced the MAF and Spider injection. With MAF unplugged, it shows the default MAG 1.62 G/S and fuel trims are close to 0. Not sure what else can cause this.
This was a hard complicated diagnostic well ✔️ done
36:16 See, with the B.B. leak you have to abandon the Maf unplug it test for the vacuum line plug it off or pinch it test. lol
all suzukis after 2005 show code p0130 for the o2 sensor and rarely show a code for lean or rich mixture. whenever we have such a code we always look at the fuel trims to tell us if the o2 sensor is at fault or not. at 7.30 in your video you do the test by pressing the gas and leaving it, there the sensor first goes lean and then rich until it goes to o ma. but the o2 sensor is fine
So i have heard of Maf Initialization being perhaps required for Mafs for sprinters it seems a hotly debated subject in sprinter forums with no conclusive yes or no .I have 2006 t1n replaced maf oem and it wont run unless Maf unplugged still , turbo wont kick on etc ,after watching some of your incredibly interesting lectures i tested voltage ,ground ,sensor ground and sensor signal all good but it still fires and dies ,then i heard about initialization perhaps being nescesary , vehicle is getting 2068-4 Maf faulty on/off ratio of reference signal is outside permissible range , i wonder if Initialization would adjust this and does it need to be a mercedes dealership to accomplish this , am glued to your inspiring lectures, thank you, if i was a little younger .....
merry christmas danners...hope your staying warm
I seen the CRC can come out and I'm like ummm that stuff ain't flammable........ know that becuase I did the same thing just a few weeks ago😂. Great video as always.
Lol filming live has its drawbacks. Thanks!
i like to use volumetric efficiency tests to rule out crappy MAF sensors. It's too bad the tires were flat - couldn't take it out for a rip.
@Scannerdanner - Paul, great video as always. The only thing I am a little lost at is why the wideband sensor showed 0 ma or stoichiometry yet the fuel trims were so negative.I know the calculated load percentage was high, but would have thought wideband would not have stayed at 0 ma. throughout all this. Thank You.
What was the issue with this car? I don't remember, I'm sorry
@ScannerDanner- this car appeared to be running rich with very negative fuel trims , but the wideband 02 sensor never moved from 0 ma of current- stoichiometric - the only pid out of whack was a high calculated load percentage. Just seems weird the wideband never moved from 0 ma of current. Thank you Paul.
That noise is caused by a problem with power or ground supply for the sensor. Maybe a fuse or just old wires. You see that a lot on cheep cars.
Hey, at 44:30, the downstream O2 sensor is sitting at around 0.8 V. Is this cause for concern?
From what I can tell, I don't think its an issue because you still have good fuel trims.
Is this a bad sensor? Is this a normal reading?
If anybody has any insight I would really appreciate it!
From
Less then a 3 liter engine you say cant use the rule of thumb with g/s based on liter of engine. I understand that as I use it. But question is will a smaller
Another great and informative video. Happy Holidays brotha Paul.
Crazy as it might sound, the gram/sec rule being less accurate under 3L displacement kind of reminds of Asimov's Foundation series, wherein a group of scientists use a mathematical formula to predict human group reactions. Bigger the group, the more accurate the prediction. Small groups being nearly impossible to chart. Closer you get to the wire, as it were, the greater the uncertainty, simply because smaller numbers are tougher to average with any accuracy. Same deal here.
how is the calculated load determined?
Great video Danner boys as always.Call me a parts snob but OEM all the way been there to many times with after market parts especially with Todays Technology.Everyone have a Merry Christmas and a safe and Happy New year.God Bless.
O.e. is original not o.e.m.
@@Ashroyer86 OOPS My Bad!!!!😁
Why do some cars not show you the upstream o2 voltage?.. But instead show you the current, i never understood that and always have a hard time diagnosing because of that
Only wideband oxygen sensors report like this. And with them comes a huge variety on what the scan data pid actually reports
HumbleMechanic said to check you out... so I did.. good stuff!
Thank you! Charles is awesome. Glad your here
Merry Christmas to the Danner clan.
You where being tested on this one Paul .. they thought they was going to but a good one on you .
Dear Paul, hello! I'm fighting now with Subaru. Engine was swapped from 1.5 A/T to 2.0 M/T, there was a lot of mess and misconnected wires. Looks like i've fixed wiring problem. But i still cant fix what is wrong with MAF. I have a new original MAF sensor. And i have around 4 volts full throttle. But my grams per second readings are 12 grams at idle, and 400 grams full throttle driving test, average 2.0 atmospheric engine. I've thought ECU was from some turbo subaru, or was re flashed. So i've bought a used ECU for this engine, and, i see the same readings. FUnny that my injection pulse at idle is 2.8 ms, it doesn't look like 3 or 4 times more. And, no backfire in exhaust. I can start engine warm, if i've had a 3-4 time more fuel, i would have drowned engine with fuel and never could start it warm. Also there is Bosch 5 wire LSU 4.2AF sensor. Reference 2.55 volts wire was swapped with pumpig current calibration wire, so my AFR was constantly 0.69 without any chance to go rich,Only lean. After i've fixed wiring problem, i have 1.0 AFR until my front AF sensor warms up, then i get -20% short term instantly, and my rear O2 sensor goes lean, low voltage.SO i assume wrong readings for my front AF sensor. But. also i have now 35 kPA at idle, it is higher than it should be. Maybe i have a good AF sensor now, but i have plugged exhaust? or Valves are not sealing combustion chamber properly? Or my AF sensor after thousands KM o fwrong connection damaged?Is that possible?
Let's move this to my forum www.scannerdanner.com it is free to join and we can try to help you there. When it comes to engine swaps, especially to a different size completely, things get complicated and I can't do this here. Too much research to do by myself to help you. Thanks! Hope to see you there.
Thanks danner. All the best to you and yours.🍻
Just a thought: if there's a frequency analyzer on the scan tool you might find out that there's a specific frequency responsible for the "hash" on the MAF signal. This does not look like random noise but specific signal pulses. Maybe the firing of injectors is responsible for the hash.
This hash is really everywhere in a car. If I'd have used sensor ground you wouldn't have seen it. But the main reason you did was with peak detect turn on, on my scope, it is sampling that screen 6 million times. If I farted you'd see it with that sample rate lol
IF WE DID A VE TEST DO YOU THINK WE WOULD HAVE A BAD VE FOR THIS ENGINE? COULD A VE TEST GIVE US A DIRECTION?
Unplug & clear codes till it goes normal?
On my Toyota 2.4L, the g/s at idle is right around 2.2-2.8. In my case, the g/s is very close to displacement at idle. I don't like my Total fuel trims though, edging up toward +10% at idle. I'll inject a flammable in the intake and see which way the trims go. I had a very brief stumble at start that cleared up when the weather got colder. Thanks for the videos, lots to learn, much to apply.
If you're under 10% you're fine. It's possible you have a small vacuum leak if it only is that way at idle.
@@ScannerDanner Thank you, SD. It could have a vacuum leak at idle and then the problem is masked while driving? I took my scan data and used max RPM and MAF, IAT and atmospheric pressure and calculated volumetric efficiency and got 110% VE. I blame the fantastic videos you put out loaded with information. I'm doomed I tell ya.
merry christmas paul and family
Hey Paul,, great flick as always.
I have a question for you. At around 27. 45 you mentioned "let's go to the graphing meter"
When do you want to use the scope vs the graphing meter and vice-versa?
This wasn't a great example of when to switch to the graphing meter. I just wanted to see what it looked like with a longer time base, without worrying about the scope sample rate (peak detect)
I'd say in short, I don't use the graphing meter very often these days unless I'm looking for a glitch or drop out on a time base longer than 5 seconds. Or if I want to graph a voltage trace that is a constant signal that shouldn't change and I'm looking for a glitch/drop out I'd definitely use the GMM for that
@@ScannerDanner thanks you very much for taking the time to answer in details, it is much appreciated. I'll add that to my book of tricks.
Happy holidays to the Danner family and long live this channel.
Thank you for all this information.
Question I got a Buick 3.8 supercharged Buick park ave and I have a p0172 I checked the term #s and seem to be ok. What can else can I look for?
Thanx ..appreciate any tips
What's the freeze frame data of that P0172 code show you for STFT, LTFT, ECT, RPM, ENGINE LOAD?
Sir in this after replace maf o2 sensor2 is going up700mv .my thinking that it reading should 450 mv.750 mv means that's system is little bet rich but fuel terms are normal .plz explain
An upstream O2 should be switching from 200-800mv and it is normal for a downstream O2 to be steady
Im randomly getting codes p2198, p2098. Also same for the other bank (2196,2096). on a 2010 Audi S5 V8. I do also get P0141 sometimes. I get LTFT -8 to -17 at most for both banks usually a bit higher for B1. Replaced OEM injectors, carbon clean, low pressure fuel pump and filter, low and high fuel pressure sensors. Plugs, coils, HPFP and pre cats O2 sensors replaced about 55k kms on it. MAF is original, I tried another one with same results. I even check the Evap purge valve. Downstream O2’s seems to be working fine, both reading about .60sh to 70sh. I removed them and cleaned. What else I could check? I want to to a flags tune on the ECU. 🤷♂️btw, cars runs great with lots of power it’s just those codes coming once in a while. Sometimes if I do startup and rigth away drive only trigger p0141 heated exhaust gas.
Your first mistake was replacing all these parts based on these codes without doing any testing. Now you've added additional variables (bad new parts) to the mix.
Define all the codes please.
I have a 20008 grand marquis it idels high until I put it a gear then It doesn't wanna accelerate after a little while I've changed spark plugs Coil packs cleaned throttle body kinda of Lost atp do you think it's my TPS ) throttle position sensor or what would you think the problem is ? Anybody!?
Merry Christmas and happy new year 🎄
Thank You Paul
Thank You Caleb
Thank You Brother Danner
My subaru forester 2.5 xt is overfeuling black smoke only on normal operating temperature start up not doing it on cold start its doing it for about 5 sec then smoke disappears do yoz think its maf?
Maybe an engine coolant temp sensor issue? Any codes? What year is your car?
Hello ScannerDanner, I need your help and advice!! I'm a diy'r, but with above average mechanical skills and general knowhow...lol. I'm looking for a pro-grade scanner, but want to save some $$$. I've allotted $500 for a scanner, but I want to ensure I have full...or near full diag capabilities with respect to being bi-directional, and the ability to scan and reset systems. Which brand would you recommend and why?
The topdon phoenix Lite, hands down. But you'll be spending around $900 for it.
Though topdon is now offering a less expensive unit that is not bluetooth but would be tethered and it goes for around $500 but if don't know if it's "full function" like the phoenix
My 2009 Honda Accord Stalled 5 years ago After I Drove Through High Waters But After A Few Tries It Started Again But With The Engine Light 5 Years Ago And Was Told The Catalytic Converter Is Bad, That’s The Code That Comes Up. As I’m Driving Sometimes Exhaust Smells Permeate The Interior Which Smell Like Rotten Eggs. Also Somehow I’ve Managed To Pass DMV Inspection 4 Years Straight With A Check Engine Light & Bad Catalytic Converter. What’s crazy is that this year I failed the DMV EMISSION TEST 4x and then I went to a shop and asked them to clear the codes and prayed and when they checked again at the DMV it passed 😂. This year they were strict but prior years they weren’t even checking! The dealership says I have Low Compression On The Number 4 Cylinder & P0420 & P0304. They say the engine was at 60psi. They performed the diagnostic in July. I heard Cataclean cleans the catalytic converter. I saw it on Amazon. What do you think? Is That Bad Catalytic Converter Endangering My Life?
Fix your misfire first before ever worrying about CAT codes. Also the rotten egg smell is not from a cat that's failing, it's from raw fuel being dumped into the cat. Most likely from the low compression cylinder.
@@ScannerDanner oh wow you’re the man! How long can I drive like this? I’ve had this issue for 5 years and somehow I keep passing inspection
@priestlygarments4004 hard to say, it certainly isn't healthy for that engine or the cats to continue to drive it with a constant misfire. It is a constant misfire right? At 60 psi of compression it has to be. I'd recommend unplugging the injector for that cylinder.
@@ScannerDanner Oh wow! What about my health? Should I be worried of carbon monoxide? Cause Honda is asking for 6,000 to put a used engine 2,000 for a used cat. I don’t even have those funds at the moment. I paid them to diagnose and all the lady said is that it’s not worth repairing to just buy a new car 🤦🏽♂️. I regret driving through that water trying to pick up an Uber rider. 😂 The car moves very well bro just the TPMS LIGHT is on and the engine light is solid. They said the TPMS sensor could be dead because the tires are perfect. Just those lights are on! Everything else is solid. I failed the DMV emissions test so I just had the dealership clear the codes temporarily and it passed.
At 50:20 O2 sensor is 0.9 steady line. Shouldn t it be oscilating from 0.2 to 0.8?
This was a downstream O2 (behind the cat) so it won't oscillate like the upstream.
@@ScannerDanner Thank you.
I thank you for learning new things
Thank you for these very instructive videos. I'm a newcomer on your channel, you are a great teacher, and I think this is what I was looking for!
What about fuel trim diagnostic strategies for cars that have MAP Sensor instead of MAF Sensor?
It's no different, but vacuum leaks certainly effect them differently. I have some classes on that. Maybe even one here on UA-cam. Check my chapter 1 playlist. I'd be there if I have it.
@@ScannerDanner Thank you! I have checked out the chapter one playlist on UA-cam and unfortunately I think there isn't.
But, please, what do you mean by vacuum leaks affect them differently.
@@ovidiumonoranu367 too long to type out, as it is very complex. I have lectures on this one my website if you can't find what your looking for here. This one in particular
www.scannerdanner.com/scannerdanner-premium-chapters/chapter-1-universal-testing-methods/chapter-1-universal-testing-methods-full/202-chapter-1-universal-testing-methods-pages-9-13.html
@@ScannerDanner OK. Thank you!
@@ovidiumonoranu367 of course!
Merry Christmas to you and your family, your brother would make a great santa claus ! Lol happy holidays
He would!!
Amazing video. Thank you Paul.
👍 you guys are the best! Happy New Year!
Danner’s bro got a backwoods blunt wrap in his shirt pocket. Nice. Blowing trees lol
Lol, it's just tobacco
"Smoke test"
I find it interesting that a doctor can practice but the general public expects techs to get it right the vary first time. Im mean look how incredibly complex these systems are.
Thanks for your video but i can' t focus you didn' t say your grandson is fine??? Your best videos with your brother he is a great man .merry christmas to you and your family.lg.
Granddaughter and yes, she is doing well. Thank you!
@@ScannerDanner thank you paul that was important to me i prayed god is with us.
Cheers you guys found that really interesting love watching your videos when you get your teeth into it and won't let go. Fuel trims.
Glad you enjoyed it. Thank you!
Suzuki that’s your first problem. Surprised the snap on had it since they’re not made anymore. I always watch diagnose Dan basically widebands are reverse of narrow band
Hey over the years I’ve been going through all your videos, including premium, wondering; how this same scenario would play out on a speed density engine with an aftermarket map sensor? I would love it if you could talk more about that style. I have a Subaru I love that I just can’t give up on, but have struggled to learn enough information to identify the problem.
Chapter 8 (psi sensors) I would cover testing MAP accuracy. Thank you!
The old smack on the component test has definitely worked for me. Especially, on Mitsubishi MAF sensors.
i have seen you clean throttle body for high engine load does that not apply in this case?
For high TPS%, not an engine load PID. Also for a false MAP sensor code
Hey I got a question this may be a little bit off subject but since we're talking about oxygen sensors on foreign cars like Hyundai's Hondas does the downstream oxygen sensor play a row in the fuel trims I have noticed several times that the downstream oxygen sensors fuel trims will be 99% and we'll never change from thatBut if you look at the downstream oxygen sensors on OBD2 or under Hyundai you will notice that they are working but the fuel trims r still stuck at 99% a lot of times I've never really wrapped my head around this
when you see downstream fuel trim at 99%, this is a data parameter that is not being use. Also, I have never, not once, seen downstream fuel trim being used with a narrow band upstream O2. Only some systems with wideband upstreams will they also use a downstream fuel trim strategy for minor corrections. In my chapter 4 and 5 playlist I have a case study on one with downstream fuel trim control. Thanks!
@@ScannerDanner thanks for the reply I really appreciate it I would love to get your book just been a little short on cash here lately I believe the car does have wideband upstreams anyways like I said thank you sir appreciate the info
@diamondstateautodiagnostic5250 oh no man I wasn't suggesting you go and buy my book I have playlists right here on UA-cam that correspond to the chapters in my book but that's all, you don't need the book to benefit from this.
here's the playlist I was talking about ua-cam.com/play/PLD2809EEC7BAAF989.html
thank you sir I really appreciate that one of these days I really would like to buy your book and join your premium Channel I love watching u videos I don't even watch TV anymore I just come home and watch your videos LOL maybe one of these days I can order a book from you I'd love to have a signed copy LOL
@@diamondstateautodiagnostic5250 I can do that 😉, just sent a signed one to the Uk
Email me at support@scannerdanner.com when you want one. Thanks again!
Good find. I agree with MAF’s are the hardest to call or take a gamble with. I’ve got lucky a few times and also not so lucky. But on another subject. Dealing with a 03 Ram that has a single misfire during decel. Full tune-up has already been done due to carbon tracking on plug. Injector also replaced to see if that was an issue. Idle and normal driving is fine. Any ideas on what to look at or test? Thanks if you can shed some light.
During decel, the injectors are cut off. What does a decel misfire feel like when non of the cylinders are firing?
@@ScannerDanner change of tone in engine. And misfire counter in scanner showing dead mis. Can’t physically feel the misfire which is odd.
@@ScannerDanner figured it out. Used a pressure transducer and saw something going on with the exhaust side. Put a scope in the cylinder and saw the valve had worn into the head and rounded the seat.
So why isn’t the upstream O2 sweeping from .1 to .9?
Because it is not a narrow band sensor. It is a wide band oxygen sensor.
Thnks Paul, from Peru
So many links. I feel like you're wiring my brain into the network matrix of your channel like I'm a cyborg. lol.. Love the rabbit holes.
Hahaha thanks for watching my friend
So you didn't make the MAF call based on the lab scope signal, you based your call on the high engine load percentage? The old and "new" MAF sensor signals look the same, or did I miss something?
That would be correct
@@ScannerDanner So, if MAF is used by the ECU to calculate engine load, why didn't we see a significant difference in wave form? Or, did you need to get more granular on the time base to see it?
@superk4562 we did in the grams per second reading at idle and also the stability of the signal. I can't remember the numbers offhand but I think the old MAF was jumping up to 4 grams per sec at idle and it was very erratic
@@ScannerDanner This is really cool! I've been troubleshooting a 1999 Ford F150, 5.4L 270K miles on it with a brand new long block. I reused some components I probably shouldn't have. I found a very small leak in the EGR valve and I replaced it. Fuel trims were 13 and 12, bank 1 and 2 respectively. I looked at the MAF, it appeared to be working but it was only reporting 4.9 g/s at idle. I installed a new MAF sensor, and g/s went to 6.2. As soon as I installed the new sensor, short-term fuel trims went negative, and started pulling the long-term fuel trim down. Now, the fuel trims are near zero, but I still can't get rid of the surge at idle; weird thing is the idle will only surge in Park or neutral. Any ideas? I've already smoke tested in the intake ... no leaks. IAC is new too.
I think it's time to get Bernies Escan with the volumetric efficiency calculation.
A great video. Thankyou
Happy holidays sir ! I wanted to ask on how you can find out right away on whethere high voltage on the scanner graph means rich or does it mean lean on this particular vehicle, and does it change from vehicle to vehicle ? Thank you so much for all your videos
It changes from car to car. They do not all report the same way.
So that's where your WOT test and deceleration test come in handy to figure out ! Ok i see thank you so much Mr. Danner you are a huge help
@@rudy2298 you got it! It is a way to force full rich and full lean to then gauge the signal of the sensor
I got confused because i wasnt paying attention to where on the video the b1s1 pid is displaying amperage, too where the other b1s2 pid is displaying voltage ! That's why on one the graph goes up and the other goes down on deceleration test
Hi Paul great channel we need more like you on the planet. Can you tell me why there was no movement on 02 bank 1 sensor 1 after fix please.
It's a wideband so they don't move the same way. When I used global data you could see the rich lean swings. I think I showed that in this video? Thanks!