I'm an OSHA trainer/ instructor I've heard lots of trainings in my time, this is one of the best detailed well said instructions/explanations I've ever heard if your not in the field of helping others you should be I can tell by your presentation you make one hell of a guy to do so your voice carries perfectly your deminer is calm dude you got a gift thank you for helping all us ... very very impressed.
Just bought a 2004 Toyota Camry LE V6 today and I’ve got to tell you this video has saved my life. I’m a noobie mechanic but I work on everything I buy myself and this was amazing thank you!!
Solved my p0174 & p0171 with 4 cans of Lucas injector cleaner. Took awhile to go through 4 tanks but light is off now. Checked by a mechanic and he said it's not throwing those codes anymore.
I'm amazed at the many attempts to fix this that had no effect. Guess you go with the easiest things/cheapest things first, so no one wanted to dive into the fuel pump as a possibility . Good video.
It's because the fuel system is continuously wearing down but it is not a material problem functionally until the engine throws a code at around 200-300k. Meanwhile, you lost gas mileage without knowing it for about 100-200k of driving.
Found my problem of a dirty MAF sensor... used MAF cleaner to clean the sensor two tiny silver wires that were heavy coated with dirt, clear the code, no problems, truck run great 👍...
Common sense is to replace or clean any cheap [arts first: plugs, coils, injectors, clean MAF sensor, replace TPS (not worth trying to clean), replace air filter, check for cracks or leaks. THEN get help from a competent mobole mechanic who knows the patterns for an old car like yours... An old Corolla will be very well known to mechanics.
Turns out it wasn't my air filter. The check engine light would sometimes go away on its own. Even after replacing both oxygen sensors, MAF sensor, headcover gasket, and smoke testing, air filter, the code kept coming back. I later discovered that my fuel injectors were in pretty rough shape. The housings were cracked, but visually nothing was clogged. I didn't really have a way of testing them, but my '02 corolla is at 230k miles, and believe they've never been replaced. So I've replaced the fuel injectors, and the car runs and accelerates a lot better now; it even starts up faster and possibly better mileage. It also has cleared the P0171 code, but I will have to drive the car a bit longer to determine it. If anyone is still having this code, I think it's worth replacing the fuel injectors. Just be careful working around gasoline, and make sure to get Denso OEM injectors. They do run a bit expensive 130$, but you won't have to worry about getting the O-rings.
I replaced my 2002 4Runner with Beck & Arnley fuel injectors. They’re the same oem fuel injectors I believe just remanufactured? Don’t quote me on that but they reuse the Aisin oem fuel injectors 100%
A bad EVAP system can also create a lean code. Disconnected the EVAP purge solenoid and drivability greatly improved and no more lean code. Yes, EVAP code was still there.
Great informational on the lean fuel code issues! You hit every bullet point dead center. This is the first video Ive seen of yours, but can guarantee I'll be looking through more for help along the way. I drive a 1st gen Expedition 4x4, and have same lean code. My issue is the front wheel hubs bring more unregulated air into the system. Great video and look forward to learning some more wisdom for Your Car Guy DR! Keep us Rollin 🛞
Great video thanks for the help on mine it was the 4 injectors after replacing everything else i wished i could have found your channel before i did all that thanks again God bless
@Your Car Guy DR. i have a 2003 Camry with 540k miles my first ever car still running like a Gem. after replacing the Evap Canister i noticed i was gettting the P0171 checked ALL the air intake sensors hoses etc. .. issue Fuel pump. thanks for helping GPA car get back on thr ROAD
Great video. Fuel pump is my problem as well. P0171 code, lean bank 1 (4 cylinder only has bank 1). 2016 Turbo Dart. looked high and low for vacuum leaks. This video confirmed my fuel pump suspicion. I replaced the original fuel pump with a Delphi unit 4 months ago. To verify the new pump is at fault I had to rig up pressure gauge in the fuel line. No pressure test port from the factory. And what do you know, 37 psi when should be 58 psi, and drops to 0 when engine is shut off.
Very informative. Thanks. The fact the dealer just threw parts at it is pretty disheartening and disgusting. Of course they charged for all that unneeded work.
Thanks for the great tips, I'm working on this issue on a 04 Camry at the moment went through all the minor steps, fuel pressure is the next move to verify it's in the right range.
I was reading your subtitles, realized I had to watch the vid 👍 I've been dealing with a p0171 since 2019 when I bought my 03 MB C230K coupe as a project car for my gf... I replaced the fuel pump yesterday, the dealer had replaced the pump in 2010 but my code is intermittent so I had a specialty shop clean my MAF sensor, passed smog recently and I didnt need an upper oxy sensor and my cat is good. I replaced the coil pak, plugs, purge valve (the shop didnt catch it) after repl. the gas tank filler neck leak (typical w/2005 model)... I bought this m271 engine because the hoses were like new until the lower radiator hose broke from the manuf. clamp/age. I currently have a EGR valve hose that inexplicably got a razor like slit after it got smogged. I wasnt showing the p0171 code so I just taped it up and heat taped it but I've never ran a pressure test on it just went underneath and took a scope to the engine to inspect the hoses as I keep them up. Post fuel filter replacement I showed a p0301 misfire cyl 1 after I swapped around the coils and plugs. Cleared the DTCs, it coughs sometimes when started but seems to have a hard start or kick like sensation felt in the pedal. I bought the injector for cyl 1 last June but the fuel additive seemed to have done the trick the last six mos. The car purrs along at 33 mpg hwy, 27 mpg city, handles hills, hard to see that I have compression issues. Gonna replace all 4 injectors and go from there. Might buy a new fuel pump, we shall see. I shoulda just put in a new MAF sensor but the shop was hesitant to put in any new parts I bought so I dont go there anymore. I caught more dirt in the engine this summer compared to last year.
If you can run a fuel pressure test before replacing the fuel pump. Low pressure can be caused by a bad pressure regulator or clogged filter among other things.
I have the same code for my corolla 2003 !! I take it to toyota dealer and they want to charge me 1100 dls for change the manifold ( they crazie ).. the word part is they told me that they not sure that fix my problem
I'm gonna put in work on an 07 Corolla and this code is one of them beside the p0420 which is a bad cat but. I'm hoping it's the maf or 02 sensor. But thank you for this video helped a lot.
Corollas are known for having this code 00-10. I already owned 2 corollas one 03,06 and they both had that issue. My experiences were that the code only came up when the weather got cold. Most of the times check engine light would turn off itself by the end of the day. The mainfold gasket is the main reason that causes this.
Intake manifold or exhaust manifold? I just replaced both so I couldn’t pin point which one it was however I believe in my case it was the exhaust manifold
The reality is that the fuel delivery system is experiencing continuous wear but the computer cutoff for when Toyota wants the customer to address it is much later than when the condition originally occurs. Clogging of the injectors can begin as early as 60-100k but nobody drives with an OBD scanner monitoring longitudinally the change in long term fuel trim. The gasket would create a lean vacuum leak. In that case the engine calls for more fuel at idle and decreases the extra demanded amount as the throttle body opens The fuel system degradation would cause a lean code after the engine is pushed. Meaning LTFT increases with more acceleration.
Great post I got a p0171 lean code so I will check my fuel pressure before I spend money on parts I dont need ps why would anyone take a beater car to the dealer lol they will charge you more than the car is worth it self lmao
Warning about those kinds fuel assemblies. I'm not special mechanic but there's like a sponge like thing inside the assembly (at least in mine there was), if there's a lot of miles on it, I'd go the expensive route and get the whole assembly. I took apart the assembly and went the cheaper route and just replaced the pump and filter. Then I discovered the sponge stuff inside, took out the fuel pressure regulator, I put a small piece of hose to where the fuel pump goes, I blew some fluid through with a squeeze bottle, the fluid was blackish silver. This only happend when I took it apart though. When doing a fuel volume test, the fuel looked clean. So I'm assuming something faulty with sponge thing as well. My car also passed the fuel pressure test but did not pass the fuel volume test.
Running in low fuel regularly leads to fuel filter issues...because the whole unit is built into the tank..it's best not to dip too low past the quater mark
Oh wow. My 2000 Toyota Corolla it has the check engine light on PO 171 . And sometimes will say misfire on cylinder number 2. And I reset the light drove it pass the emissions and right away after I drove away from the shop light came back. I reset it few times and keep coming. So this is amazing video I’m going to look for that diagnostic
First thing to check about code p0171 is any hose crack (leak) check well all hoses if any cracked just replace it and you are done and you don’t have to check other causes like fuel pump fuel injection fuel pressure …. It’s symptom is the engine shaking hard at start and the rpm is high, second cause is a leak in the intake manifold, Start by the easy cause and if all hoses are ok then check the other probable causes
Hi there. I got the same diagnostic. Because i think a mecánic took the second heater core out without my permittion. I only have one heater core which heats in cold weather. Do you think is that the problem. He also change my maf sensor and this issue started. Reads code P0300 that im having issues with my maf sensor now. But know they ran another diagnostic. 2 weeks after maf sensor didn't show. But im getting a most likely manifold gasket. Auto parts told me you might have a vacuum leak. Could it be Because my reservoir container underneath i have a leak?
My Toyota V6 was doing same thing replaced everything MAF, Oxygen Sensors, throttle disassembly and cleaning to dealership no avail only thing that worked was several aggressive treatments with Cheveron fuel injector cleaner just got it to pass smog. Might have to drop tank.
Injectors don't affect fuel pressure. They certainly can be clogged and cause a lean condition. Pump or regulator. Even a clogged fuel filter would have to create a massive drop in flow to affect pressure.
Gregory Fairchild I am guessing you have never seen a leaking injector or injector that has worn to the point of severe over fueling. As a certified master tech with more than 20 years of experience I have seen this on multiple vehicles from multiple brands
@@YourCarGuyDR Wouldn't a leaking injector,or over fueling injector, cause a rich condition, or even a misfire? I would think you might even end up with fuel in the oil that would also contribute to a rich condition. Some basic diagnostics by the dealer should have found this easily...I would think this would have exhibited relatively normal, or just slightly positive fuel trims at idle that got worse with RPM and/or load. A wide open throttle run while watching the O2 would have shown the O2's go lean...that really only leaves a MAF (which the dealer totally guessed on) or fuel delivery. Can't believe they did a head gasket. That's just malpractice.
@@YourCarGuyDR Do you think the 23 gas mileage on my 01 corolla is the cause of the mass air flow sensor. There is just p0420 code pending and fault. Idk why the car get bad gas mileage. Its a 2001 toyota corolla ce, 3 speed automatic.
@@YourCarGuyDR yea, Im beginning to think its just the 3 speed automatic, so the car never goes into overdrive. However even in the city its bad gas mileage. So idk.
Wow! Thanks for your descriptive video. I’ll check the fuel psi on my 97 Camry and the fuel filter. Bought the car used and not sure if the filter has ever been changed.
Accept that most dealers and mechanic shops make money selling parts. The labor is not a money-maker. I found 2 mobile mechanics and have a "fall-back" if 1 is unavailable and never quibble about their labor cost and if they are willing to explain or show me what they are doing... I pay close attention. That's how I learned to set up electric guitars and now I can do nearly all of it myself. Basic tools and knowledge is all it takes and it can save a lot of annoyance. .
We sell our parts at the same cost available to you when you shop at automotive parts retailers. Stop spreading false information. Labor is a 50/50 split. You when some you lose some. You Never know what youre gonna run into during a job.
Hello, I recently allowed myself to get scammed and purchased an 02 Corolla that had this hidden P0171 Code & a salvage title among other issues. They had disabled the check engine light so that it wouldn't come on. Anyways, I am trying to learn as much as I can about this PO171 issue and I suspect it is a fuel delivery problem as well, for this specific vehicle. Upon watching your video, I tried to locate where I could connect a fuel pressure gauge, but as far as I can tell, the area in which you showed in this video, does not disconnect from the fuel rod. It is withstanding the force of simply pulling the line off. In case anyone reads this comment, where exactly do I connect the fuel pressure gauge & where can I buy this 02 Corolla adapter kit necessary to establish this connection? I cannot locate a kit for this make/model online. Thank you regardless for your informative video.
I have a 2000 model which looks pretty much the same, if I remember correctly we might've taken that fuel hose off at the end closest to the engine. Might be worth a try but I don't know what I'm doing, I know we checked fuel pressure though.
There is a connection coming from near the firewall to the engine. It requires a special line tool to release. You can get a fuel pressure test kit that will have the needed adapters. If I remember right my kit was around $100.00 online. Not name brand but it works for the times I need it.
Some good info, and insight, on this problem. Thank you! My 02 Tacoma started acting up last night (Check engine light came on....then it didnt want to maintain idle, and would fall off flat at WOT on the way home). Luckily, it's a manual trans, or AAA would have encompassed the rest of my evening. Interestingly, I had JUST dumped a bottle of Dry Gas (with injector cleaner), in it yesterday because of all the temperature swings, and rain we've had on the East Coast, lately. Hrrrmm Limped it home, and pulled the engine codes : PO171, and PO136. I'll start with the O2 sensor, check for vacuum leaks, and move on from there. If fuel pressure is at spec, and the injectors are all at their respective factory specs for resistance, do you think a clogged CAT could contribute to this issue in any conceivable way? Thanks for any reply, and your time. "Liked, and subbed." 👍
If it just started happening after the dry gas was added I would try to get to a second tank of fuel and see if it clears up. Clogged catalytic converters are pretty rare.
All the banter .. my rule of being a poor kid trying to diag .. start with the cheap-free solves first .. clean the MAF .. change the air filter, check the fuel pressure .. didn’t do the trick well at least you can eliminate that and you probably needed to do it anyway .. work your way up the cost/maintenance ladder .. I dunno maybe I’m stupid
AVRAHAM BREA the intake manifold gasket was changed during the head gasket job the dealer did. As much as I have heard that it is a common failure on these engines none of the ones that I have run into have had intake gaskets leaking.
I have that exact issue. I was trying to fix it for five months and changed o2 sensors and Maf sensor with tune up. I don't see your video on the fuel pump! I need to replace the whole kit. Do you have that video? Thank you very much!
What about a bad gas cap??? Could that be (Maybe) a problem? I have a 02 Corolla and it's throwing me the P0171 code. Cleaned MAF sensor and new O2 sensor, but noticed when I added gas it didn't make the whistling noise when gas cap was removed, no pressure. I'm not a mechanic at all and it's probably a dumb question just curious to ask. Anything would help. Thanks
Yes,I had that issue a couple of times in my 5.7 litre Chevrolet LS1 V8 powered Holden Commodore & it was caused by a leaky fuel pressure regulator inside the fuel tank. I've had an issue recently where the oxygen sensor on the left bank gets stuck at a long term fuel trim reading of 25%,the right bank is at 21.9%, I've recently had a leaky fuel cap issue cause a check engine indicator to become switched on & I got a P0171 code & sometimes a P0174 code to be stored inside the PCM,the P0442 isn't applicable in Australia because Holden didn't fit a fuel tank pressure sensor. I was thinking about checking the fuel pressure but the fuel sender unit is fairly new,the fuel filter is nearly due for replacement as well so I'll replace that, I am looking at swapping the oxygen sensors over & there's other things to Try such as cleaning the MAF meter. If worse comes to worse,I'll build a smoke machine to find out if I have an air leak,it could possibly be caused by a sticking fuel injector as well,the thing is the engine starts too easily & runs too smooth to say it has a problem !
I did the following and still running lean *Changed oxygen sensors twice. *Changed fuel pump *Clean Maf Sensor *Intake manifold *Welded a crack in the exhaust manifold. What am I missing?
It is possible you have a bad MAF sensor. I would verify fuel psi and inspect for vacuum leaks. One or more faulty or plugged fuel injectors could also cause an issue.
IF you see that code on the Chevy 1.4L Turbo found in the Chevy Sonic, or Chevy Cruze, AND the 1.8L non-turbo...a great place to start is the plastic valve cover gasket. The design is the failure point. No more than $210 for the part, and with a torque wrench, an easy fix.
That’s right these car dealership can take your money and they still didn’t fix the problem you should sue and get your money back they are money hungry I have the same problem and things you don’t need and you only going because your check engine light on I will never do that again try and fine the right mechanic that knows what he’s doing or ask a good friend where they take there car that they can recommend never go to a car dealership.......
Thanks for this video. The other day I was on a hill and the car was in reverse and I didn’t realize… I took my foot of the brake and it started rolling forward. I went to step on the brakes and it was stiff and all of the lights on the dash board came on…. i quickly put the car in neutral and turned it off for a few and it drove fine. Now i notice the brakes get stiff and dont grab if i ‘pump the brake pedal’ several times and now my Check engine, vsc and other light came on. I have the code P0171… could this incident cause a P0171? any idea why this would happen or did this lean fuel code just happen to come on coincidently from a separate issue? any help you can offer is appreciated.
This is most likely coincidence. The brakes and the P0171 are likely not related unless you have a massive vacuum leak. The brake booster works off of vacuum on most vehicles.
The fuel pressure can be affected by several things. First if the fuel filter is plugged. Next if the pickup screen is plugged. Next would be the fuel pressure regulator. If all of those are fine and the pump isn’t producing adequate pressure or volume then the pump needs to be replaced.
Been getting P0171 but mostly when it's cold and within a few minutes of starting. Checked with vacuum gauge and it was normal, but did that test on a warm day and in semi direct sun. No abnormal idle that I can see. Then I did a fuel pressure test. Used rubber adapter and brass fitting which came with the gauge to connect the gauge hose to a T adapter. Start engine and it reads steady 40. Then I noticed that the pressure pushed the hose half off the brass fitting and there's a strong stream of gas spraying inside the engine area. Checked all connections in case I didn't have it right. The hose fit well and snug on the knurled teeth of the brass connector. Start up again and it pushed the hose about half way off and again gas spraying out steady, and reading 40 again until I quickly turned it off. My question is: If the pressure is 40 with this much gas spraying out, do you think actual pressure is probably in the normal range? If so, then with the code happening in he cold, all I can think of is to replace the intake manifold gasket. What do you think?
Thanks for the vid i have a feeling my 08 xb may have a fuel pump issue got the car with 180,000 might have to check the pump a lot of the parts on this car seem original🤔🤔🤔
Hi! Have A The Same Code [P0171] On My 2004 Ford Ranger 3.0, No Vacuum Leaks, Replaced The Fuel Pump, Fuel Filter & Mass Air Flow Sensor, What Else Could It Be?
I dunno about on rangers, but on the F150's the power steering sensor, and the coolant temp sensor share the same harness. for me a short in the power steering wire kept causing the coolant temp sensor to send improper data to the PCM. only way i found out that was the issue was after being as stumped as you was. I played the "unplug something and see if it fixes it" game. after plugging the power steering sensor harness, my truck went from rough idle to normal. So some sensor changing and rewiring is what my issue was...........i pray you dont have to play the electrical game. but after that issue was gone.
I have a 2000 Corolla... replace all 4 injectors as a good start and new NGK platinum plugs with 4 coils. Routine stuff and any 'mobile mechanic' can do it cheap.... you buy the correct parts and hire him to install them!
How were you sure it was the injectors? My 2000 is at 180k so it could be that, but I don't like throwing parts at things. That's how yo incorrectly replace head gaskets, as was mentioned.
@@Johnslist I replaced injectors at about 220K miles at the advice of a skilled mobile mechanic (worked on racing cycles and cars) who has a sophisticated scanner. A 'miss' I resolved this year with 1 'ignition coil wire' for about $70 and 2 minutes time ...
I got a 2009 Toyota Rav 4 2.5 cyl, engine runs lean and takes longer than usual to start up and feels like it wants to die out sometimes, no abs light engine and traction light on. I'm thinking its injectors or spark plugs, checked the air/vacuum lines and everything seems to be okay car only has 102000 miles so I'm a little confused as to what the problem could be
Taking longer to start and during out sounds like a fuel supply issue. I would check fuel pressure first to verify that it is correct. Also a vacuum leak between the mass air sensor and the intake could cause similar issues.
I installed an aftermarket filter ( not a pod filter but a replacement after market ). It gave this code. Can I conclude that this filter lets through more air than the MAF has accounted for?
No, the engine will adjust to the filter and the mass air sensor reads after the filter. It is more likely that you have a vacuum leak allowing air to enter the intake between the mass air sensor and the cylinder head.
@@YourCarGuyDR well te reason asking, it gives no error with the original filter but as soon as I install the pod filter I get this error. When I swap back to the original it disappears right away.. very odd
Well I do have this code but I don't think it has anything to do with the fuel pump or fuel filter because I replaced both of them twice within 3 months. But the code was actually reading p0340. Not a camshaft position sensor. I don't care what anybody says. That is a bad fuel pump. Because even after I replaced the camshaft sensor with that code it didn't start. It was a fuel pump. It's common sense if you don't hear the fuel pump buzz. It's bad. My car has been having trouble starting like as if the fuel pump was bad. My car has had a fuel system problem even before the fuel pump went out and ever since I replaced the fuel pump fuel filter the gas cap p0440 And the O2 sensors p0171. The issue is still happening. The engine hesitates to start due to lack of fuel. It's not the spark plugs or air. I know that for a fact. Like I said my car has had a fuel delivery system for a while now. I've been replacing a different part each month. I'm really hoping that it's not a bad timing chain because that can cause a car to have these exact issues as well. Most of the time when my car starts it starts right away but it has like a 1 or 2-second delay. But still starts right away. P0171 bank 1 running too lean Can cause a car to stall hesitate And hesitate to go up a hill or from a complete stop. And most definitely feel like the transmission is sifting hard. My car has a lot of issues but I'm starting to think That the po171 and p0440 Is a blown head gasket because it's leaking oil. That's the only other thing I can think of besides a bad timing chain or a bad fuel injector. But I hooked up three different scan tooland 1 says PO171 bank 1 running lean. And the other scan tool says P0171 O2 sensor heater circuit malfunction. And the 3rd one say p0440 and p0171. Large Evap leak and bank 1 running lean. And no seafoam does not work. That is a bunch of crap. It only made things worse. Trust me and those fuel injector cleaners don't work either or the fuel system cleaners. Problem with the fuel system. None of those feel additives are going to work. Trust me, it's common sense. Tired of wasting money. Trying to figure out what the issue is. But you mentioned head gasket leak and I think that is the only thing that it could be besides a timing chain. Because The engine is leaking oil. And it's leaking onto the exhaust causing the car to sting under the car, not under the hood. So if my car is leaking oil it could very much be a head gasket leak and can leak oil on other metal parts including the timing chain. You are definitely right about people not checking for fuel pressure, but people also don't check the timing chain that has a lot to do with it too. But I know for a fact it's not the fuel pump on my car or the fuel filter cuz I replace those things twice.
I have a 1997 Lincoln Town Car has the same codes with a check engine light on. Drives great around town. but on the highway cruise control set to 68 miles per hour the second I hit a hill incline the car will downshift to boost power but has no pep at the same time the po171 and po174 codes and engine light kick on if I have cleared the codes prior to this test run. With possibilities being from an O2 sensor vacuum leak or fuel pressure where do I begin. NOTE my scanner shows me my battery volts from the OBD2 port connection is reading 12.5 volts compared to other vehicles at my disposal that's almost 2 volts less could this be causing poor fuel pressure not having ample power to the fuel pump
Claudio Fagundes as long as you are over 12 volts you are fine. Since you are getting both the p0171 and p0174 I doubt that your issue is an oxygen sensor. I would check for vacuum leaks. I would also do a fuel psi test.
I’m going to try this on my 350z I have had that code for a couple months now and today heading home from work it dropped rpms and didn’t want to a accelerate when I step on the gas.
It depends on the climate that you are in. In colder weather it is good to give the engine just a bit of time to get the oil warm and flowing properly.
Hi, where do you buy the injectors? I have a 2001 corolla and replaced the engine with a 2005. I get a p171 trouble code at 3mph at 700 rpm idle. Would I get the 2005 injectors or 2001? Also knocking under steep uphill. Ive replaced both o2s, cat and fuel pump. I will test for vacuum leaks with a smoke machine. Car has 300k miles. Thanks in advance.
This can be a bit of a dilemma. If you are using the 2001 computer you will likely want the 2001 injectors. The knocking may be caused by a fuel issue but can also be a timing issues or a bad bearing. One other thing to be aware of is that there may have been a change in the camshafts between the two years. This could included differences in variable cam timing. If possible you would want the computer to match the year of the engine. I have in the past on these cars put the older cam in the newer cylinder head since I was running the old computer. As far as purchasing injectors I usually search online and be sure to look at reviews and verify that you are getting what you pay for.
@@YourCarGuyDR thanks again. I only get the misfires like twice a year when i go to Victorville. But all around it gets great milage and good power. I just need fix the code before my next smog check. I dont have the original camshaft anymore, but thats a good point. Maybe ill find a vacuum leak.Thanks
Play previously had a po171 code just recently within a month. It's running very underpowered hard going up hills etc.. About 9 months ago I was driving on the highway and the car crashed right out just stalled right out. I don't know if the fuel filter was checked and I know there are one in the same mounted on top of the fuel pump that was changed over so the new fuel pump would also include the new fuel filter especially on that car is that correct? Can anyone tell me this otherwise I'm going to have to die back in and replace the fuel filter if that's the problem
It depends on if you bought a complete fuel pump assembly that included the filter and pressure regulator or if they just put a new pump in the original assembly.
Great vid!👍🏻I Hava po171 code primarily in the winter. The car purrs - no symptoms whatsoever. Should I do a fuel press test? If it is a pump prob, can I swap out the fuel filter Only,i’m guilty of driving around w/ low fuel levels😅
same on my corolla 06 p0171 no leak nothing. engine stalling in summer above 30 celcius I waited 5 minutes and the car started again 3 time this summer and if I leave the air conditioning on the idle in summer after 10 minutes the engie stall on its own but works very well in winter but only have bad cold idle they work like a camed car lol but after the car runs very well for all the winter I did everything ... I have the car for 2 years it had the code p0171 since purchase written on the obd2 305 000km... clean maf check o2 sensor up and down collant refill fan perfect temp perfect 86c in summer radiator perfect no leak no intake leak no smoke dozen burn oil no code when stall no code when stall no code when run like a cammed car
How do these idiots get away with it ? You did way over $ 1000.00 of work and the car does the EXACT same thing ! I would only pay DEALER NET COST on the parts , NO LABOR ! Or they get sued in small claims court ! The question , when you get a work order to approve is " will it fix the car " ? Remember , they are " experts " !
Bill Smith I agree. It is frustrating seeing what happens sometimes at the dealerships. I know there are good ones out there but there are also times that people get taken.
The last time I did this the entire assembly was expensive, however the individual parts are not. You can do it either way depending on your budget and desire to do the little bit of extra assembly. I would recommend changing the filter either way.
Buick 2000 3.8....my warning light problem began about 2 months ago. First it said gas cap loose, I cleaned it and that was solved...Then it became slightly difficult to start, so I would slightly tap the gas pedal and it would start right up. After a couple days it would start up normally again on the first turn of the key like it always has and still does now........a couple weeks ago the yellow check engine light came on and the code came up PO171. Then it when out by it self a couple days later, then came on again, and went out again...During all of this I have watched my mileage very closely, and my instant mileage for highway driving is 29 mpg, which I the same has it has always been, and the average overall mileage is 22, like it always has been......do you have any idea what the problem would most likely be? Also during this whole time the car has been idling and running very good......Thanks for any suggestions...............
I got a 2003 toyota matrix, when cold it start right up, but after engine got warm and try to turn it back on it will take a lot of time to get it run, so it might be that i need a fuel pump?
I have the same code in my Toyota Yaris sedan 1.5 2009 and the fuel pressure is 37 PIS so that's mean the pump or fuel filter,or pressure regulator is the problem.I will replace all because it too much work check every part with the time
my Avalon 02 had same code to lean, checked lines good, but car only turned on to a bogle off. then i removed the air filter and car turned on so just got a new engine air filter in there and its all good now.14$
What could be the cause of a P0171 on a 2016 Jeep Patriot Latitude 2.0 we just replaced the MAP sensor but the vehicle still has a rough idle and the rpms run high while driving on the freeway approximately 65-70 mph the rpms are jumping up to 2200-2700 rpms. What could cause that? My husband already checked for vacuum leaks and says he can't find any obvious leaks. We just replaced the map sensor thinking that would fix it but it didn't so I'm thinking it could possibly be a bad Throttle Body w/Actuator IAC Idle Air Control or a TPS Position Sensor or even possibly a upstream 02 sensor. If anyone else can give me some advice on what I should fix next I would greatly appreciate it thank you!
It is important to do a little more diagnosing before replacing anything. You want to make sure that the symptoms you are chasing match the code. Are the rpm’s running higher than they did before at the same speed? Is the transmission shifting into a lower gear due to lack of power? Does the vehicle seem to want to accelerate without throttle input. Some of this can help narrow down your problem.
How can i fix a p0172 problem on a 99 toyota tacoma 3.4 v6. Any suggestions please comment i already replaced coils, spark plug wires and spark plugs and code still pops up. Please comment below. Thanks for the help in advance.
@@YourCarGuyDR thanks. I'll have to do some more checking. Replaced the o2 sensor (today) and added fuel injector cleaner (a week ago) but the check engine light came back on.
Running rich can be caused by a faulty mass flow sensor, a leaking or stuck open injector, a stuck fuel psi regulator, low compression in one or more cylinders or even loss of spark in a cylinder.
Your car guy i got a 1993 toyota supra that starts for a couples seconds thn dies no matter how much i try it dies i checked my fuel pressure gauge read 36psi at idle thn i press on gas it would go lower 32psi any ideas
A couple of things I would check. First I would inspect the air intake piping from the air filter to the engine for any cracks or bad spots. I would also check the throttle position sensor for a dead spot. You can look up how to test the throttle position sensor.
I'm an OSHA trainer/ instructor I've heard lots of trainings in my time, this is one of the best detailed well said instructions/explanations I've ever heard if your not in the field of helping others you should be I can tell by your presentation you make one hell of a guy to do so your voice carries perfectly your deminer is calm dude you got a gift thank you for helping all us ... very very impressed.
Thank you. I appreciate your kind words.
@@YourCarGuyDR very welcome!
If you want to monitize utube and commercials
@@MrRusell86 but its my car not his car, you're wrong
Lol osha trainer here and I agree
Just bought a 2004 Toyota Camry LE V6 today and I’ve got to tell you this video has saved my life. I’m a noobie mechanic but I work on everything I buy myself and this was amazing thank you!!
Solved my p0174 & p0171 with 4 cans of Lucas injector cleaner. Took awhile to go through 4 tanks but light is off now. Checked by a mechanic and he said it's not throwing those codes anymore.
I'm amazed at the many attempts to fix this that had no effect. Guess you go with the easiest things/cheapest things first, so no one wanted to dive into the fuel pump as a possibility . Good video.
It's because the fuel system is continuously wearing down but it is not a material problem functionally until the engine throws a code at around 200-300k. Meanwhile, you lost gas mileage without knowing it for about 100-200k of driving.
Found my problem of a dirty MAF sensor... used MAF cleaner to clean the sensor two tiny silver wires that were heavy coated with dirt, clear the code, no problems, truck run great 👍...
Common sense is to replace or clean any cheap [arts first: plugs, coils, injectors, clean MAF sensor, replace TPS (not worth trying to clean), replace air filter, check for cracks or leaks. THEN get help from a competent mobole mechanic who knows the patterns for an old car like yours... An old Corolla will be very well known to mechanics.
@@YouDontKnowMe210tx MAF sensor cleaner. Can’t do much else, they’re fragile
Turns out it wasn't my air filter. The check engine light would sometimes go away on its own. Even after replacing both oxygen sensors, MAF sensor, headcover gasket, and smoke testing, air filter, the code kept coming back. I later discovered that my fuel injectors were in pretty rough shape. The housings were cracked, but visually nothing was clogged. I didn't really have a way of testing them, but my '02 corolla is at 230k miles, and believe they've never been replaced. So I've replaced the fuel injectors, and the car runs and accelerates a lot better now; it even starts up faster and possibly better mileage. It also has cleared the P0171 code, but I will have to drive the car a bit longer to determine it. If anyone is still having this code, I think it's worth replacing the fuel injectors. Just be careful working around gasoline, and make sure to get Denso OEM injectors. They do run a bit expensive 130$, but you won't have to worry about getting the O-rings.
I replaced my 2002 4Runner with Beck & Arnley fuel injectors. They’re the same oem fuel injectors I believe just remanufactured? Don’t quote me on that but they reuse the Aisin oem fuel injectors 100%
Where did you buy them?
A bad EVAP system can also create a lean code. Disconnected the EVAP purge solenoid and drivability greatly improved and no more lean code. Yes, EVAP code was still there.
Wait you Disconnected it and then connected it back on or ?….
How did the car start when you disconnected the purge valve ? Just curious
Yeal my old man 2006 Mazda 6 have struck open purge vale make that code before .
Greatest training video I've ever seen. You go through all the issues it could be and the not wanting to start is the issue I have. Thank you!
Great informational on the lean fuel code issues! You hit every bullet point dead center. This is the first video Ive seen of yours, but can guarantee I'll be looking through more for help along the way. I drive a 1st gen Expedition 4x4, and have same lean code. My issue is the front wheel hubs bring more unregulated air into the system. Great video and look forward to learning some more wisdom for Your Car Guy DR!
Keep us Rollin 🛞
How would wheel hubs bring in unmetered air?
@riflebear1711 First gen ford expeditions four wheel drive Vacuum lines
My Lord you are outstanding 🙌 so precise and perfect on all the info THANK YOU for your efforts in helping all of us!!!
Great video thanks for the help on mine it was the 4 injectors after replacing everything else i wished i could have found your channel before i did all that thanks again God bless
@Your Car Guy DR. i have a 2003 Camry with 540k miles my first ever car still running like a Gem. after replacing the Evap Canister i noticed i was gettting the P0171 checked ALL the air intake sensors hoses etc. .. issue Fuel pump. thanks for helping GPA car get back on thr ROAD
540k miles ?????
extremely helpful, have a 00 Tacoma and just got a 171 code, yay...
Wow! Very detailed, informative, professional, and awesome insight. Great presentation buddy.
Great video. Fuel pump is my problem as well. P0171 code, lean bank 1 (4 cylinder only has bank 1). 2016 Turbo Dart. looked high and low for vacuum leaks. This video confirmed my fuel pump suspicion. I replaced the original fuel pump with a Delphi unit 4 months ago. To verify the new pump is at fault I had to rig up pressure gauge in the fuel line. No pressure test port from the factory. And what do you know, 37 psi when should be 58 psi, and drops to 0 when engine is shut off.
Very informative. Thanks. The fact the dealer just threw parts at it is pretty disheartening and disgusting. Of course they charged for all that unneeded work.
Super helpful video! Thank you for getting right down to business and not rambling for 10 minutes first
Thanks you really help any information is very important to those don't have money to pay to the mechanic Thanks
Thanks for the great tips, I'm working on this issue on a 04 Camry at the moment went through all the minor steps, fuel pressure is the next move to verify it's in the right range.
Any update? I have the same car
I was reading your subtitles, realized I had to watch the vid 👍 I've been dealing with a p0171 since 2019 when I bought my 03 MB C230K coupe as a project car for my gf... I replaced the fuel pump yesterday, the dealer had replaced the pump in 2010 but my code is intermittent so I had a specialty shop clean my MAF sensor, passed smog recently and I didnt need an upper oxy sensor and my cat is good. I replaced the coil pak, plugs, purge valve (the shop didnt catch it) after repl. the gas tank filler neck leak (typical w/2005 model)...
I bought this m271 engine because the hoses were like new until the lower radiator hose broke from the manuf. clamp/age. I currently have a EGR valve hose that inexplicably got a razor like slit after it got smogged. I wasnt showing the p0171 code so I just taped it up and heat taped it but I've never ran a pressure test on it just went underneath and took a scope to the engine to inspect the hoses as I keep them up.
Post fuel filter replacement I showed a p0301 misfire cyl 1 after I swapped around the coils and plugs. Cleared the DTCs, it coughs sometimes when started but seems to have a hard start or kick like sensation felt in the pedal. I bought the injector for cyl 1 last June but the fuel additive seemed to have done the trick the last six mos. The car purrs along at 33 mpg hwy, 27 mpg city, handles hills, hard to see that I have compression issues.
Gonna replace all 4 injectors and go from there. Might buy a new fuel pump, we shall see. I shoulda just put in a new MAF sensor but the shop was hesitant to put in any new parts I bought so I dont go there anymore. I caught more dirt in the engine this summer compared to last year.
If you can run a fuel pressure test before replacing the fuel pump. Low pressure can be caused by a bad pressure regulator or clogged filter among other things.
Wow! bet they got soaked at the dealership for the head gasket job that they didn't even need!
jlc7300 yes they did.
Yeah 4 real! I'd be pissed.
I have the same code for my corolla 2003 !! I take it to toyota dealer and they want to charge me 1100 dls for change the manifold ( they crazie ).. the word part is they told me that they not sure that fix my problem
That's a crime😥.. they could hv done a Compression test instead of removing the Head and Still not solving the problem
Sounds like a very dishonest dealership (is that redundant?). Simple tests would have shown a blown head gasket.
Quick and down to the point awesome video guys thank you for posting
I'm gonna put in work on an 07 Corolla and this code is one of them beside the p0420 which is a bad cat but. I'm hoping it's the maf or 02 sensor. But thank you for this video helped a lot.
I’m having the Same issue on my 2006 corolla p0420 and p0171 did you get the codes to go away??
Glad you got throw parts at it. There weren't many left. Good job.
Luckily My Fuel Pump was $130 with everything assembled in One 🙌🏽💯🙏🏽👏🏽
I have a 2002 Corolla S. 217000 miles almost. Thank you sir.
Corollas are known for having this code 00-10. I already owned 2 corollas one 03,06 and they both had that issue. My experiences were that the code only came up when the weather got cold. Most of the times check engine light would turn off itself by the end of the day. The mainfold gasket is the main reason that causes this.
Intake manifold or exhaust manifold? I just replaced both so I couldn’t pin point which one it was however I believe in my case it was the exhaust manifold
The reality is that the fuel delivery system is experiencing continuous wear but the computer cutoff for when Toyota wants the customer to address it is much later than when the condition originally occurs. Clogging of the injectors can begin as early as 60-100k but nobody drives with an OBD scanner monitoring longitudinally the change in long term fuel trim.
The gasket would create a lean vacuum leak. In that case the engine calls for more fuel at idle and decreases the extra demanded amount as the throttle body opens
The fuel system degradation would cause a lean code after the engine is pushed. Meaning LTFT increases with more acceleration.
Great post I got a p0171 lean code so I will check my fuel pressure before I spend money on parts I dont need ps why would anyone take a beater car to the dealer lol they will charge you more than the car is worth it self lmao
a trick : you can watch series at Flixzone. Been using it for watching loads of movies recently.
@Orion Sonny definitely, I've been watching on Flixzone} for months myself :)
@Orion Sonny Definitely, I've been watching on Flixzone} for months myself :)
@Orion Sonny Yea, have been using flixzone} for since november myself :D
Came for a tidbit I got a whole great deal of info thank you so much
Warning about those kinds fuel assemblies. I'm not special mechanic but there's like a sponge like thing inside the assembly (at least in mine there was), if there's a lot of miles on it, I'd go the expensive route and get the whole assembly. I took apart the assembly and went the cheaper route and just replaced the pump and filter. Then I discovered the sponge stuff inside,
took out the fuel pressure regulator, I put a small piece of hose to where the fuel pump goes, I blew some fluid through with a squeeze bottle, the fluid was blackish silver. This only happend when I took it apart though. When doing a fuel volume test, the fuel looked clean. So I'm assuming something faulty with sponge thing as well. My car also passed the fuel pressure test but did not pass the fuel volume test.
So well explained /clarity 👏🏾 👌🏽
Had the exact same issue and solved it with a fuel pump/filter assembly. Turned out to be the filter clogged.
Running in low fuel regularly leads to fuel filter issues...because the whole unit is built into the tank..it's best not to dip too low past the quater mark
@@TheMuzikall - Yes, thank you. It was a used vehicle I had just bought. I usually try and keep my gas above half tank.
Oh wow. My 2000 Toyota Corolla it has the check engine light on PO 171 . And sometimes will say misfire on cylinder number 2. And I reset the light drove it pass the emissions and right away after I drove away from the shop light came back. I reset it few times and keep coming. So this is amazing video I’m going to look for that diagnostic
Mouse Gipson with yours make sure to check for an intake manifold vacuum leak at cylinder #2.
Damn..best video yet on this topic...thx a bunch
First thing to check about code p0171 is any hose crack (leak) check well all hoses if any cracked just replace it and you are done and you don’t have to check other causes like fuel pump fuel injection fuel pressure …. It’s symptom is the engine shaking hard at start and the rpm is high, second cause is a leak in the intake manifold, Start by the easy cause and if all hoses are ok then check the other probable causes
Hi there. I got the same diagnostic. Because i think a mecánic took the second heater core out without my permittion. I only have one heater core which heats in cold weather. Do you think is that the problem. He also change my maf sensor and this issue started. Reads code P0300 that im having issues with my maf sensor now. But know they ran another diagnostic. 2 weeks after maf sensor didn't show. But im getting a most likely manifold gasket. Auto parts told me you might have a vacuum leak. Could it be Because my reservoir container underneath i have a leak?
Thank you for perfect explaination. 👍
Had the same code and was lucky that all it took was cleaning the MAF sensor.
My Toyota V6 was doing same thing replaced everything MAF, Oxygen Sensors, throttle disassembly and cleaning to dealership no avail only thing that worked was several aggressive treatments with Cheveron fuel injector cleaner just got it to pass smog. Might have to drop tank.
Injectors don't affect fuel pressure. They certainly can be clogged and cause a lean condition.
Pump or regulator.
Even a clogged fuel filter would have to create a massive drop in flow to affect pressure.
Gregory Fairchild I am guessing you have never seen a leaking injector or injector that has worn to the point of severe over fueling. As a certified master tech with more than 20 years of experience I have seen this on multiple vehicles from multiple brands
@@YourCarGuyDR Wouldn't a leaking injector,or over fueling injector, cause a rich condition, or even a misfire? I would think you might even end up with fuel in the oil that would also contribute to a rich condition. Some basic diagnostics by the dealer should have found this easily...I would think this would have exhibited relatively normal, or just slightly positive fuel trims at idle that got worse with RPM and/or load. A wide open throttle run while watching the O2 would have shown the O2's go lean...that really only leaves a MAF (which the dealer totally guessed on) or fuel delivery. Can't believe they did a head gasket. That's just malpractice.
@@YourCarGuyDR Do you think the 23 gas mileage on my 01 corolla is the cause of the mass air flow sensor. There is just p0420 code pending and fault. Idk why the car get bad gas mileage. Its a 2001 toyota corolla ce, 3 speed automatic.
SlikzPlayz the code will have some effect on fuel mileage. However there are many factors that can also have an impact on the mileage.
@@YourCarGuyDR yea, Im beginning to think its just the 3 speed automatic, so the car never goes into overdrive. However even in the city its bad gas mileage. So idk.
At least he's diagnosing and replacing afterwards...instead of using the customers money to diagnose an issue...
Wow! Thanks for your descriptive video. I’ll check the fuel psi on my 97 Camry and the fuel filter. Bought the car used and not sure if the filter has ever been changed.
Honestly. .I am yet to see a Fuel Injected Toyota or Japanese car with a Fuel Pump problem...it's unheard of..MAF issues ..yes..Fuel pump...nope
Simple explanation , very useful info , thx.
Accept that most dealers and mechanic shops make money selling parts. The labor is not a money-maker. I found 2 mobile mechanics and have a "fall-back" if 1 is unavailable and never quibble about their labor cost and if they are willing to explain or show me what they are doing... I pay close attention. That's how I learned to set up electric guitars and now I can do nearly all of it myself. Basic tools and knowledge is all it takes and it can save a lot of annoyance. .
We sell our parts at the same cost available to you when you shop at automotive parts retailers. Stop spreading false information. Labor is a 50/50 split. You when some you lose some. You Never know what youre gonna run into during a job.
@@RedSrhRed I took my post from a pro mechanic with a large following in UA-cam vids. What you say is just what you say. It maye or may not be true.
Hello,
I recently allowed myself to get scammed and purchased an 02 Corolla that had this hidden P0171 Code & a salvage title among other issues. They had disabled the check engine light so that it wouldn't come on. Anyways, I am trying to learn as much as I can about this PO171 issue and I suspect it is a fuel delivery problem as well, for this specific vehicle. Upon watching your video, I tried to locate where I could connect a fuel pressure gauge, but as far as I can tell, the area in which you showed in this video, does not disconnect from the fuel rod. It is withstanding the force of simply pulling the line off. In case anyone reads this comment, where exactly do I connect the fuel pressure gauge & where can I buy this 02 Corolla adapter kit necessary to establish this connection? I cannot locate a kit for this make/model online.
Thank you regardless for your informative video.
I have a 2000 model which looks pretty much the same, if I remember correctly we might've taken that fuel hose off at the end closest to the engine. Might be worth a try but I don't know what I'm doing, I know we checked fuel pressure though.
There is a connection coming from near the firewall to the engine. It requires a special line tool to release. You can get a fuel pressure test kit that will have the needed adapters. If I remember right my kit was around $100.00 online. Not name brand but it works for the times I need it.
Some good info, and insight, on this problem. Thank you!
My 02 Tacoma started acting up last night (Check engine light came on....then it didnt want to maintain idle, and would fall off flat at WOT on the way home). Luckily, it's a manual trans, or AAA would have encompassed the rest of my evening.
Interestingly, I had JUST dumped a bottle of Dry Gas (with injector cleaner), in it yesterday because of all the temperature swings, and rain we've had on the East Coast, lately. Hrrrmm
Limped it home, and pulled the engine codes : PO171, and PO136. I'll start with the O2 sensor, check for vacuum leaks, and move on from there.
If fuel pressure is at spec, and the injectors are all at their respective factory specs for resistance, do you think a clogged CAT could contribute to this issue in any conceivable way?
Thanks for any reply, and your time. "Liked, and subbed." 👍
If it just started happening after the dry gas was added I would try to get to a second tank of fuel and see if it clears up. Clogged catalytic converters are pretty rare.
Did you end up fixing it?
All the banter .. my rule of being a poor kid trying to diag .. start with the cheap-free solves first .. clean the MAF .. change the air filter, check the fuel pressure .. didn’t do the trick well at least you can eliminate that and you probably needed to do it anyway .. work your way up the cost/maintenance ladder .. I dunno maybe I’m stupid
This is my method as well. It's better than starting with a full engine replacement.
No mention of intake manifold gasket those are pretty common on these
AVRAHAM BREA the intake manifold gasket was changed during the head gasket job the dealer did. As much as I have heard that it is a common failure on these engines none of the ones that I have run into have had intake gaskets leaking.
Be suspicious of the new cars with plastic intake manifolds.
I have that exact issue. I was trying to fix it for five months and changed o2 sensors and Maf sensor with tune up. I don't see your video on the fuel pump! I need to replace the whole kit. Do you have that video? Thank you very much!
Replacing The Fuel Pump Corolla
ua-cam.com/video/aGx2zgXY5CE/v-deo.html
Thank you for sharing! Great right on the spot brief explanation
This is the exact same problem my son is having with his '07 Corolla
Same here. Did he get it fixed and if so what was the issue please help
@@dre6036 did you get it fixed
Injector , fuel pump and regulator. Oe injectors
What about a bad gas cap??? Could that be (Maybe) a problem? I have a 02 Corolla and it's throwing me the P0171 code. Cleaned MAF sensor and new O2 sensor, but noticed when I added gas it didn't make the whistling noise when gas cap was removed, no pressure. I'm not a mechanic at all and it's probably a dumb question just curious to ask. Anything would help. Thanks
The bad gas cap won’t cause this code. It could cause a code for an evaporative emissions leak.
Def earned a sub for this. This vid was extremely helpful.
The poor owner... head gasket, o2 sensor, MAF... oh my christ.
Yes,I had that issue a couple of times in my 5.7 litre Chevrolet LS1 V8 powered Holden Commodore & it was caused by a leaky fuel pressure regulator inside the fuel tank.
I've had an issue recently where the oxygen sensor on the left bank gets stuck at a long term fuel trim reading of 25%,the right bank is at 21.9%, I've recently had a leaky fuel cap issue cause a check engine indicator to become switched on & I got a P0171 code & sometimes a P0174 code to be stored inside the PCM,the P0442 isn't applicable in Australia because Holden didn't fit a fuel tank pressure sensor.
I was thinking about checking the fuel pressure but the fuel sender unit is fairly new,the fuel filter is nearly due for replacement as well so I'll replace that, I am looking at swapping the oxygen sensors over & there's other things to
Try such as cleaning the MAF meter.
If worse comes to worse,I'll build a smoke machine to find out if I have an air leak,it could possibly be caused by a sticking fuel injector as well,the thing is the engine starts too easily & runs too smooth to say it has a problem !
Where is the link for the fuel pump replacement? I'd like to see that. Great vid!
Sorry I didn’t get back to you sooner. Let me know if you still need it.
I did the following and still running lean
*Changed oxygen sensors twice.
*Changed fuel pump
*Clean Maf Sensor
*Intake manifold
*Welded a crack in the exhaust manifold.
What am I missing?
It is possible you have a bad MAF sensor. I would verify fuel psi and inspect for vacuum leaks. One or more faulty or plugged fuel injectors could also cause an issue.
can a crack/leak exhaust manifold cause p0171 code and vacuum leak symptoms? 2005 accord 2.4
An exhaust leak can cause a PO171 code particularly if it is at the exhaust manifold upstream of the oxygen sensor.
@@YourCarGuyDR thanks! I will remove the manifold and inspect it.
Very helpful thank you for showing this VD love it
IF you see that code on the Chevy 1.4L Turbo found in the Chevy Sonic, or Chevy Cruze, AND the 1.8L non-turbo...a great place to start is the plastic valve cover gasket. The design is the failure point. No more than $210 for the part, and with a torque wrench, an easy fix.
Appreciate,that's probably my Problem!!!
That’s right these car dealership can take your money and they still didn’t fix the problem you should sue and get your money back they are money hungry I have the same problem and things you don’t need and you only going because your check engine light on I will never do that again try and fine the right mechanic that knows what he’s doing or ask a good friend where they take there car that they can recommend never go to a car dealership.......
Thanks for this video. The other day I was on a hill and the car was in reverse and I didn’t realize… I took my foot of the brake and it started rolling forward. I went to step on the brakes and it was stiff and all of the lights on the dash board came on…. i quickly put the car in neutral and turned it off for a few and it drove fine.
Now i notice the brakes get stiff and dont grab if i ‘pump the brake pedal’ several times and now my Check engine, vsc and other light came on. I have the code P0171… could this incident cause a P0171? any idea why this would happen or did this lean fuel code just happen to come on coincidently from a separate issue? any help you can offer is appreciated.
This is most likely coincidence. The brakes and the P0171 are likely not related unless you have a massive vacuum leak. The brake booster works off of vacuum on most vehicles.
Hi since you say CoDE P0171 can possibly be the Gas pump , is there anyway to clean the gas pump and possibly it can deliver more gas ?
The fuel pressure can be affected by several things. First if the fuel filter is plugged. Next if the pickup screen is plugged. Next would be the fuel pressure regulator. If all of those are fine and the pump isn’t producing adequate pressure or volume then the pump needs to be replaced.
Been getting P0171 but mostly when it's cold and within a few minutes of starting. Checked with vacuum gauge and it was normal, but did that test on a warm day and in semi direct sun. No abnormal idle that I can see.
Then I did a fuel pressure test. Used rubber adapter and brass fitting which came with the gauge to connect the gauge hose to a T adapter. Start engine and it reads steady 40. Then I noticed that the pressure pushed the hose half off the brass fitting and there's a strong stream of gas spraying inside the engine area. Checked all connections in case I didn't have it right. The hose fit well and snug on the knurled teeth of the brass connector. Start up again and it pushed the hose about half way off and again gas spraying out steady, and reading 40 again until I quickly turned it off.
My question is: If the pressure is 40 with this much gas spraying out, do you think actual pressure is probably in the normal range?
If so, then with the code happening in he cold, all I can think of is to replace the intake manifold gasket. What do you think?
Thanks for the vid i have a feeling my 08 xb may have a fuel pump issue got the car with 180,000 might have to check the pump a lot of the parts on this car seem original🤔🤔🤔
On the manifold is has 3 tubes connections for the hose..which one goes where...please help. The middle does it go PCV valve?
3 tubes
Hi! Have A The Same Code [P0171] On My 2004 Ford Ranger 3.0, No Vacuum Leaks, Replaced The Fuel Pump, Fuel Filter & Mass Air Flow Sensor, What Else Could It Be?
I dunno about on rangers, but on the F150's the power steering sensor, and the coolant temp sensor share the same harness. for me a short in the power steering wire kept causing the coolant temp sensor to send improper data to the PCM. only way i found out that was the issue was after being as stumped as you was. I played the "unplug something and see if it fixes it" game. after plugging the power steering sensor harness, my truck went from rough idle to normal. So some sensor changing and rewiring is what my issue was...........i pray you dont have to play the electrical game. but after that issue was gone.
I have a 2000 Corolla... replace all 4 injectors as a good start and new NGK platinum plugs with 4 coils. Routine stuff and any 'mobile mechanic' can do it cheap.... you buy the correct parts and hire him to install them!
How were you sure it was the injectors? My 2000 is at 180k so it could be that, but I don't like throwing parts at things. That's how yo incorrectly replace head gaskets, as was mentioned.
Parts changer
@@Johnslist I replaced injectors at about 220K miles at the advice of a skilled mobile mechanic (worked on racing cycles and cars) who has a sophisticated scanner. A 'miss' I resolved this year with 1 'ignition coil wire' for about $70 and 2 minutes time ...
I got a 2009 Toyota Rav 4 2.5 cyl, engine runs lean and takes longer than usual to start up and feels like it wants to die out sometimes, no abs light engine and traction light on. I'm thinking its injectors or spark plugs, checked the air/vacuum lines and everything seems to be okay car only has 102000 miles so I'm a little confused as to what the problem could be
Taking longer to start and during out sounds like a fuel supply issue. I would check fuel pressure first to verify that it is correct. Also a vacuum leak between the mass air sensor and the intake could cause similar issues.
I installed an aftermarket filter ( not a pod filter but a replacement after market ). It gave this code. Can I conclude that this filter lets through more air than the MAF has accounted for?
No, the engine will adjust to the filter and the mass air sensor reads after the filter. It is more likely that you have a vacuum leak allowing air to enter the intake between the mass air sensor and the cylinder head.
@@YourCarGuyDR well te reason asking, it gives no error with the original filter but as soon as I install the pod filter I get this error. When I swap back to the original it disappears right away.. very odd
Well I do have this code but I don't think it has anything to do with the fuel pump or fuel filter because I replaced both of them twice within 3 months. But the code was actually reading p0340. Not a camshaft position sensor. I don't care what anybody says. That is a bad fuel pump. Because even after I replaced the camshaft sensor with that code it didn't start. It was a fuel pump. It's common sense if you don't hear the fuel pump buzz. It's bad. My car has been having trouble starting like as if the fuel pump was bad. My car has had a fuel system problem even before the fuel pump went out and ever since I replaced the fuel pump fuel filter the gas cap p0440 And the O2 sensors p0171. The issue is still happening. The engine hesitates to start due to lack of fuel. It's not the spark plugs or air. I know that for a fact. Like I said my car has had a fuel delivery system for a while now. I've been replacing a different part each month. I'm really hoping that it's not a bad timing chain because that can cause a car to have these exact issues as well. Most of the time when my car starts it starts right away but it has like a 1 or 2-second delay. But still starts right away. P0171 bank 1 running too lean Can cause a car to stall hesitate And hesitate to go up a hill or from a complete stop. And most definitely feel like the transmission is sifting hard. My car has a lot of issues but I'm starting to think That the po171 and p0440 Is a blown head gasket because it's leaking oil. That's the only other thing I can think of besides a bad timing chain or a bad fuel injector. But I hooked up three different scan tooland 1 says PO171 bank 1 running lean. And the other scan tool says P0171 O2 sensor heater circuit malfunction. And the 3rd one say p0440 and p0171. Large Evap leak and bank 1 running lean. And no seafoam does not work. That is a bunch of crap. It only made things worse. Trust me and those fuel injector cleaners don't work either or the fuel system cleaners. Problem with the fuel system. None of those feel additives are going to work. Trust me, it's common sense. Tired of wasting money. Trying to figure out what the issue is. But you mentioned head gasket leak and I think that is the only thing that it could be besides a timing chain. Because The engine is leaking oil. And it's leaking onto the exhaust causing the car to sting under the car, not under the hood. So if my car is leaking oil it could very much be a head gasket leak and can leak oil on other metal parts including the timing chain. You are definitely right about people not checking for fuel pressure, but people also don't check the timing chain that has a lot to do with it too. But I know for a fact it's not the fuel pump on my car or the fuel filter cuz I replace those things twice.
I have a 1997 Lincoln Town Car has the same codes with a check engine light on. Drives great around town. but on the highway cruise control set to 68 miles per hour the second I hit a hill incline the car will downshift to boost power but has no pep at the same time the
po171 and po174 codes and engine light kick on if I have cleared the codes prior to this test run. With possibilities being from an O2 sensor vacuum leak or fuel pressure where do I begin. NOTE my scanner shows me my battery volts from the OBD2 port connection is reading 12.5 volts compared to other vehicles at my disposal that's almost 2 volts less could this be causing poor fuel pressure not having ample power to the fuel pump
Claudio Fagundes as long as you are over 12 volts you are fine. Since you are getting both the p0171 and p0174 I doubt that your issue is an oxygen sensor. I would check for vacuum leaks. I would also do a fuel psi test.
I’m going to try this on my 350z I have had that code for a couple months now and today heading home from work it dropped rpms and didn’t want to a accelerate when I step on the gas.
Having a similar problem with my Maxima. Did you get yours fixed?
@@maliquepaulk3014 yea I just changed my gallery gasket and put another new set of spark plugs and the solve the problem
was it the fuel pump?
I didn't realize that you're supposed to warm up your car. Is this normal practice?
It depends on the climate that you are in. In colder weather it is good to give the engine just a bit of time to get the oil warm and flowing properly.
I subscribed and liked. Good video. I will check my fuel pressure, and see what's up. :)
thanx great video!! Where do i get the parts cheaply for the fuel pump? any link to video to fix it?
Rock Auto or any online retailer you can good price on it. I use EBay a lot for new parts.
ua-cam.com/video/aGx2zgXY5CE/v-deo.html
@@YourCarGuyDR can you send me the list of parts to fix the pump. thanx
@@aronklein1167 I would do the pump, filter and pressure regulator.
Hi, where do you buy the injectors? I have a 2001 corolla and replaced the engine with a 2005. I get a p171 trouble code at 3mph at 700 rpm idle. Would I get the 2005 injectors or 2001? Also knocking under steep uphill. Ive replaced both o2s, cat and fuel pump. I will test for vacuum leaks with a smoke machine. Car has 300k miles. Thanks in advance.
This can be a bit of a dilemma. If you are using the 2001 computer you will likely want the 2001 injectors. The knocking may be caused by a fuel issue but can also be a timing issues or a bad bearing. One other thing to be aware of is that there may have been a change in the camshafts between the two years. This could included differences in variable cam timing. If possible you would want the computer to match the year of the engine. I have in the past on these cars put the older cam in the newer cylinder head since I was running the old computer. As far as purchasing injectors I usually search online and be sure to look at reviews and verify that you are getting what you pay for.
@@YourCarGuyDR thanks again. I only get the misfires like twice a year when i go to Victorville. But all around it gets great milage and good power. I just need fix the code before my next smog check. I dont have the original camshaft anymore, but thats a good point. Maybe ill find a vacuum leak.Thanks
Play previously had a po171 code just recently within a month. It's running very underpowered hard going up hills etc..
About 9 months ago I was driving on the highway and the car crashed right out just stalled right out. I don't know if the fuel filter was checked and I know there are one in the same mounted on top of the fuel pump that was changed over so the new fuel pump would also include the new fuel filter especially on that car is that correct? Can anyone tell me this otherwise I'm going to have to die back in and replace the fuel filter if that's the problem
It depends on if you bought a complete fuel pump assembly that included the filter and pressure regulator or if they just put a new pump in the original assembly.
Great vid!👍🏻I Hava po171 code primarily in the winter. The car purrs - no symptoms whatsoever. Should I do a fuel press test? If it is a pump prob, can I swap out the fuel filter Only,i’m guilty of driving around w/ low fuel levels😅
A fuel pressure test is always a good idea. If you pressure is good you can move on to other items. If it is low you should be able to easily fix it.
same on my corolla 06 p0171 no leak nothing. engine stalling in summer above 30 celcius I waited 5 minutes and the car started again 3 time this summer and if I leave the air conditioning on the idle in summer after 10 minutes the engie stall on its own but works very well in winter but only have bad cold idle they work like a camed car lol but after the car runs very well for all the winter
I did everything ... I have the car for 2 years it had the code p0171 since purchase written on the obd2
305 000km...
clean maf
check o2 sensor up and down
collant refill
fan perfect temp perfect 86c in summer
radiator perfect no leak
no intake leak
no smoke dozen burn oil
no code when stall
no code when stall
no code when run like a cammed car
Check your fuel pressure.
You are the best
It's always simple for some reason it's always a vacuum leak or what about intake manifold gasket use do a smoke test first
You got my sub 👍 well said now makes it more easy for my to explain
F
How do these idiots get away with it ? You did way over $ 1000.00 of work and the car does the EXACT same thing ! I would only pay DEALER NET COST on the parts , NO LABOR ! Or they get sued in small claims court ! The question , when you get a work order to approve is " will it fix the car " ? Remember , they are " experts " !
Bill Smith I agree. It is frustrating seeing what happens sometimes at the dealerships. I know there are good ones out there but there are also times that people get taken.
Thanks for Awesome explanation 👏
Have this issue with my 99’ ls400 but runs good and idles perfect. Not sure if I need to replace o2 sensor because maf is clean
It’s rare that this code is actually caused by the O2 sensor. It is more often a vacuum leak.
Hello, great video! So to order the built in filter do I search for built in filter? Fuel filter assambly? Or how? Thanks!
The last time I did this the entire assembly was expensive, however the individual parts are not. You can do it either way depending on your budget and desire to do the little bit of extra assembly. I would recommend changing the filter either way.
Buick
2000 3.8....my warning light problem began about 2 months ago. First
it said gas cap loose, I cleaned it and that was solved...Then it
became slightly difficult to start, so I would slightly tap the gas
pedal and it would start right up. After a couple days it would start
up normally again on the first turn of the key like it always has and
still does now........a couple weeks ago the yellow check engine
light came on and the code came up PO171. Then it when out by it self
a couple days later, then came on again, and went out again...During
all of this I have watched my mileage very closely, and my instant
mileage for highway driving is 29 mpg, which I the same has it has
always been, and the average overall mileage is 22, like it always
has been......do you have any idea what the problem would most likely
be? Also during this whole time the car has been idling and running
very good......Thanks for any suggestions...............
bonnie johnson because of the difficulty starting I would suspect a fuel pressure issue.
@@YourCarGuyDR Thanks, that's what i thought also, but it has been starting flawlessly ever sense that few days of mishap about two months ago....
bonnie johnson is the code still coming on?
@@YourCarGuyDR it comes on for a couple days, and then goes out by itself , and then comes back on a coupe days later....
bonnie johnson I would get the fuel pressure checked.
I got a 2003 toyota matrix, when cold it start right up, but after engine got warm and try to turn it back on it will take a lot of time to get it run, so it might be that i need a fuel pump?
It is possible. But you want to test the pressure before just buying parts.
Done! When cold pressures goes up to 50psi, after 30 mins running it drops to 20psi
@@honduras25 definitely you have low fuel pressure. The regulator is most likely your issue. I would do the pump at the same time.
Do you have a source for the flow matched reman injectors? I need a set, so many copies out there
You are correct there are a lot of copies. I generally rely on reviews from other purchasers to get a good set. So far I have had good luck.
@@YourCarGuyDR thanks!
I have the same code in my Toyota Yaris sedan 1.5 2009 and the fuel pressure is 37 PIS so that's mean the pump or fuel filter,or pressure regulator is the problem.I will replace all because it too much work check every part with the time
my Avalon 02 had same code to lean, checked lines good, but car only turned on to a bogle off. then i removed the air filter and car turned on so just got a new engine air filter in there and its all good now.14$
What could be the cause of a P0171 on a 2016 Jeep Patriot Latitude 2.0 we just replaced the MAP sensor but the vehicle still has a rough idle and the rpms run high while driving on the freeway approximately 65-70 mph the rpms are jumping up to 2200-2700 rpms. What could cause that? My husband already checked for vacuum leaks and says he can't find any obvious leaks. We just replaced the map sensor thinking that would fix it but it didn't so I'm thinking it could possibly be a bad Throttle Body w/Actuator IAC Idle Air Control or a TPS Position Sensor or even possibly a upstream 02 sensor. If anyone else can give me some advice on what I should fix next I would greatly appreciate it thank you!
It is important to do a little more diagnosing before replacing anything. You want to make sure that the symptoms you are chasing match the code. Are the rpm’s running higher than they did before at the same speed? Is the transmission shifting into a lower gear due to lack of power? Does the vehicle seem to want to accelerate without throttle input. Some of this can help narrow down your problem.
How can i fix a p0172 problem on a 99 toyota tacoma 3.4 v6. Any suggestions please comment i already replaced coils, spark plug wires and spark plugs and code still pops up. Please comment below. Thanks for the help in advance.
Do you say the majority of reasons for P0171 is lower fuel pressure?
Shawn Lee no, normally the p0171 is cause by a vacuum leak.
So if the fuel pressure is fine then the o2 sensor would be a likely problem? Assuming no leaks anywhere
wrenchlix with no vacuum leaks and good fuel pressure it could be one of the following, mass air sensor, O2 sensor, or a plugged injector.
@@YourCarGuyDR thanks. I'll have to do some more checking. Replaced the o2 sensor (today) and added fuel injector cleaner (a week ago) but the check engine light came back on.
Can that work for a car that is burning too rich.?help plz
Running rich can be caused by a faulty mass flow sensor, a leaking or stuck open injector, a stuck fuel psi regulator, low compression in one or more cylinders or even loss of spark in a cylinder.
@@YourCarGuyDR thanks for the response
Your car guy i got a 1993 toyota supra that starts for a couples seconds thn dies no matter how much i try it dies i checked my fuel pressure gauge read 36psi at idle thn i press on gas it would go lower 32psi any ideas
A couple of things I would check. First I would inspect the air intake piping from the air filter to the engine for any cracks or bad spots. I would also check the throttle position sensor for a dead spot. You can look up how to test the throttle position sensor.