P0171 Explained - System TOO LEAN (Bank 1)

The FIXD wireless OBD2 scanner and free app for iPhone and Android translates your check engine light into plain English so you can rest easy. In this video, we explain what OBD2 code P0171 means and possible causes.
P0171 means your engine is running too lean (too much air or not enough fuel) in bank 1 of your engine. Combustion engines run most efficiently when they maintain an air-fuel mixture ratio of 14.7 parts air to 1 part fuel. When there are more than 14.7 parts air to 1 part fuel in the air-fuel mixture, a lean condition exists and code P0171 is triggered.
The lean condition can be caused by a vacuum leak, which introduces more air into the air-fuel mixture, or by a weak fuel system, which does not input enough fuel into the air-fuel mixture. To keep the engine running properly, the powertrain control module (PCM) tries to compensate for the lean condition by injecting more fuel to the mixture in an effort to maintain the proper 14.7:1 ratio. When these adjustments become too large, code P0171 is triggered.
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0:00 P0171 - System Too Lean in Bank 1
0:09 P0171 is caused when the ratio of fuel to oxygen is off in Bank 1
0:29 Lean relates to ratio of fuel to oxygen
0:40 Power Train Control Module (PCM)
1:10 Possible Causes of P0171
1:51 Visit our blog to learn more about P0171
2:06 Happy Driving!
#FIXD #P0171 #checkenginelight

Пікірлер: 83

  • @BobSnyderAuto
    @BobSnyderAuto3 жыл бұрын

    Love the straightforward explanation! The best part of this video is that it explains WHY this is happening. Too many times there is no diagnosis, simply just throw this O2 sensor on and it is fixed...It is so important to know HOW the symptoms are related to the solution.

  • @Cayoroots
    @Cayoroots5 жыл бұрын

    This channel needs more followers

  • @fixdapp

    @fixdapp

    5 жыл бұрын

    We appreciate that, and sometimes think the same thing. :D

  • @guesswhomartin9249
    @guesswhomartin92494 жыл бұрын

    Wow... You explained it the best so far. I just joined you, and I hit the like button.

  • @humbertocastillo6043
    @humbertocastillo6043 Жыл бұрын

    Fixd is very good , i can find right way the problem when i have the engine light on...i love it. thank you.

  • @timpace9216
    @timpace9216 Жыл бұрын

    Great information and explanation

  • @BORICUACHANNEL
    @BORICUACHANNEL2 жыл бұрын

    Love Your Video

  • @fixdapp

    @fixdapp

    2 жыл бұрын

    Thank you, Boricua, for the kind words! We appreciate you taking the time to watch. 😊

  • @anthonyibarra7512
    @anthonyibarra75125 жыл бұрын

    Very informative....Thank You

  • @oddsins4350
    @oddsins43504 жыл бұрын

    I pulled the fuel pump unit from the gas tank and changed the filter it fix my rough idle and long and no crank problems. I had this dam code for 2 years I did everything it’s still there I give up screw this dam car

  • @sramBC

    @sramBC

    3 жыл бұрын

    Change gas cap. Maybe it’s the ecm

  • @tonylopez6585

    @tonylopez6585

    3 жыл бұрын

    Maybe it’s faulty header gaskets?

  • @anthonybrowning6833

    @anthonybrowning6833

    5 ай бұрын

    Vacuum leak try a smoke machine 2:00

  • @fatdudeswag404
    @fatdudeswag4046 жыл бұрын

    Great to know

  • @fixdapp

    @fixdapp

    6 жыл бұрын

    Glad to have helped! Let us know if you need anything else.

  • @brandon9161
    @brandon91614 жыл бұрын

    How do I know which nine it is, p0171 could be either one too much 02 or 2 little fuel?

  • @Richard-vl2vz
    @Richard-vl2vz4 жыл бұрын

    Just found my type,, thank you P 0717. Let's get rich!!!

  • @imatter4619
    @imatter46193 жыл бұрын

    Great video. My 97 Oldsmobile 88 has this code and on Top of that the car doesn't start half the time. As I turn the key it makes it's usual noise but doesn't start, and eventually it starts and runs fine. PLEASE HELP

  • @ogredz3361
    @ogredz33615 жыл бұрын

    I have this same code but it shows bank 1 and bank 2 too lean. Would this be the same for O2 sensors

  • @shadzuchiha6691
    @shadzuchiha66913 жыл бұрын

    Can also be caused by Dirty intake filters

  • @user-zc1rb6lu4c
    @user-zc1rb6lu4c9 ай бұрын

    The problem was a vacuum leak I had disconnected the tubing running from the exhaust manifold to the EGR valve because of a low EGR flow code. The reason for that was because I couldn't get the bolts out of the EGR valve without them snapping so I was using this method to spray through the EGR valve 2 possibly unstick it if it was stuck and maybe possibly the cleaner would go through the EGR completely and possibly break the carbon up in the EGR channels. The cleaner was a seafoam product used to inject through air ducts while engine was running. It seemed to have fixed the problem but not entirely I may have to do it again and see where that lands me since I can't get the EGR valve off without snapping the bolts.

  • @SchrodingersBox
    @SchrodingersBox4 жыл бұрын

    Not too bad. 98% of people would just change an O2 only because the code mentions the words O2 sensor. Actually, O2 sensor is not the most common culprit. In fact, if the LTFT is able to set a functional baseline with a zero’d STFT, it is mathematically impossible the O2 can be faulty. But no, no- people just rev up their parts cannon anyway.

  • @mharradine57

    @mharradine57

    4 жыл бұрын

    Ha, hilarious. I just mentioned your video as a reply to one of the comments on here after someone complained about other videos going on and on...This tool just pisses me off, making people think it is going to tell them what part to change. People were doing this with Actron code readers in 1996. The video even helped direct them to replace the o2 sensor! I noticed that there were no videos telling what part to change with a U1000 code..."Just tell me what to start swapping!"

  • @LonelyBrownEyes1977

    @LonelyBrownEyes1977

    4 жыл бұрын

    Code readers are just that, they are code readers and not a problem solver. They give a code, its thru PROPER DIAGNOSTICS that you find the real problem and can fix the issue. Codes merely just point you in a direction to get started. Many other issues can set a MIL indicator or check engine light. Problem with todays economy is vehicle owners DO NOT want to pay the labor price to have their stuff diagnosed and fixed, although they'll stupidly spend money just throwing parts at it and eventually getting lucky only afyer replacing everything that wasnt even the problem.

  • @reignman0311

    @reignman0311

    4 жыл бұрын

    lol, exactly,when I saw the ad for it, I laughed coz it does not tell you exactly what it is and how much it's gonna cost, like you said, it gives you a place to start looking at just as this vid is saying,was like 6 different parts that could be bad or not working correctly,

  • @bowendevin2070

    @bowendevin2070

    2 жыл бұрын

    i guess I am kinda randomly asking but do anyone know a good website to stream newly released movies online ?

  • @bodenthatcher6738

    @bodenthatcher6738

    2 жыл бұрын

    @Bowen Devin Flixportal :P

  • @RussellBooth1977
    @RussellBooth19774 жыл бұрын

    I keep on getting a P0171 code in a Chevrolet LS1 V8 powered car,the fuel pressure seems to be low at 50 PSI & there seems to be air in the fuel when checked the fuel volume,the fuel pressure should be 55-62 PSI. So,the first thing I'll change will be the fuel filter before anything else,I've already changed the fuel filler cap which was leaking air into the fuel tank,note no P0442 is listed for my car as the engine is in a Holden who didn't fit a fuel tank pressure sensor !

  • @RitchardWithaT
    @RitchardWithaT3 жыл бұрын

    Wouldn’t bank 2 be lean if it was a bad fuel pump tho?

  • @jagr06
    @jagr062 жыл бұрын

    Sadly for me i've invested tons of money fixing the MAFS and other shit and it still is on. When I had them check in the morning before I left for work they literally said nothing is wrong inside and maybe I should change gas stations or fuel types. And unfortunately that too did nothing the past 6 months BUT when I needed to have a oil change the light decided to turn off when they decided to do my inspection Early July and It popped back up the following day. At this point i feel like the light and the code is all bullshit, as it's trolling me.

  • @fordaman2360
    @fordaman23605 жыл бұрын

    total babe and awesome presentation

  • @godfredfosu1828

    @godfredfosu1828

    5 жыл бұрын

    Good

  • @virusboy07

    @virusboy07

    5 жыл бұрын

    @TheJudge01 indeed.

  • @66coltrane

    @66coltrane

    4 жыл бұрын

    You call that a babe ! She’s cute but a babe is tooooo far.

  • @jawharris

    @jawharris

    4 жыл бұрын

    @@66coltrane If she were in a bikini in the video, would you believe she was a babe? If she were in that bikini, I suspect you would give her no credibility. She is a good balance.

  • @adrianhayden7036

    @adrianhayden7036

    3 жыл бұрын

    She don't need no bikini to be a babe.. I'll give credit, where credit is due! She's welcome in my shop anyday..!

  • @heathcalvert1319
    @heathcalvert13193 жыл бұрын

    1999 5.9 Durango help got a p0171 code how do i get rid of it

  • @Abdulaziz-lo6nx
    @Abdulaziz-lo6nx5 жыл бұрын

    I am today check mazda6 2016 show dashboard engine check light.. After i am connect the diagnostic cable show me P0171 Lenk bank 2

  • @vihumajimartz6881

    @vihumajimartz6881

    3 жыл бұрын

    How to fix that because I have a Mazda 6 2014 y the same code P0171 and I don’t know what to do

  • @stacyg3425
    @stacyg34253 жыл бұрын

    Can this have anything to do with the muffler or muffler valve. I just bought a used car and 3 days later the engine oil turned on with codes P0171 and P0174 . I contacted the dealer and they said they’d check it but it was most likely a valve in the muffler? I don’t know much about cars. Help would be great.

  • @Lafortune100

    @Lafortune100

    2 жыл бұрын

    how did u fix it , i got p0171 and been trynna fix it for 2 days

  • @adrianperez1550
    @adrianperez15503 жыл бұрын

    Does this make the car shut down ?

  • @ceasarslimer68
    @ceasarslimer684 жыл бұрын

    Could it make a car not go over 15 mph

  • @jaemajor
    @jaemajor2 ай бұрын

    Ended up being my exhaust manifold.. 1k job

  • @stevemendess2683
    @stevemendess26834 жыл бұрын

    Not a serious problem,change the spark plugs yesterday when off..n light came back on..after 24 hrs

  • @JeffTheHokie
    @JeffTheHokie4 жыл бұрын

    Mine's throwing that code, but running so rich it's painting the driveway under the exhaust pipe black. It's not a vacuum leak or a fuel shortage. Something is giving the computer an incorrect reading

  • @NEKROBAT666
    @NEKROBAT6664 жыл бұрын

    Damn, soo many things can be wrong 😩

  • @stevemendess2683

    @stevemendess2683

    4 жыл бұрын

    but all very very minor

  • @stevemendess2683

    @stevemendess2683

    4 жыл бұрын

    @@reignman0311 but it's not urgent,,of course is a major difference after a spark plug change oil change etc,,but if the basics are done..then that check engine light shouldn't b on

  • @mrlambo2972

    @mrlambo2972

    3 жыл бұрын

    @@reignman0311 on my friends bmw it was a dirty injector and what I did was add Fuel system All in one cleaner and it took 2 of them and it did the job. I told him drive it for a while and yes the issue fixed while he was driving 💯💯 I checked everything else and no other issue was found

  • @IYBN8623
    @IYBN86235 жыл бұрын

    ok so what are the dangers of continuing to drive it for a day or two till you can get it into the shop??

  • @lankmasterplaysminecraft2858

    @lankmasterplaysminecraft2858

    4 жыл бұрын

    Nick M I’ve been driving with mine on for like 6 months. A day or 2 is fine

  • @darthtrader1027

    @darthtrader1027

    4 жыл бұрын

    I'm gonna start by cleaning my mass airflow sensor and putting in a clean air filter... If that doesn't do it, I'm gonna get some fuel injector cleaner and spray around the intake manifold to see if it has any effect on the engine idle sound... If it does then I need to replace the intake gasket... If that doesn't fix it I'm gonna have to throw a new air flow sensor in. Hoping I guessed right with the MAF sensor.

  • @elizabethlamboy-wilson7335

    @elizabethlamboy-wilson7335

    4 жыл бұрын

    I''ve been driving my Toyota 2003 Camry with this check engine light on for 2 months with this code. It's not that big a deal but in order to make sure you have no engine issues in the future, try to get it fixed as soon as you can.

  • @Richard-vl2vz

    @Richard-vl2vz

    4 жыл бұрын

    For myself, I needed to tighten my exhaust flanges right out of the header on the passenger side..car runs brand new....

  • @stevemendess2683

    @stevemendess2683

    4 жыл бұрын

    @@elizabethlamboy-wilson7335 mine was the spark plugs...then the light return this morningsmh,,I too own a 02 camry with nearly 300kmile

  • @PinkysHouse
    @PinkysHouse Жыл бұрын

    What if it's both P0174 and P0171

  • @3dentertainment301
    @3dentertainment3013 жыл бұрын

    Good lord she is VERY ATTRACTIVE. Now that's someone I'd like to see every day ;)

  • @Brunotravelchannel
    @Brunotravelchannel4 жыл бұрын

    Could a bad rear main seal cause it also?

  • @fixdapp

    @fixdapp

    4 жыл бұрын

    That is a good question. The answer is YES it can. A leaking or failing rear main seal can cause the fuel trims to run lean by allowing excess air into the system. Many modern engines in cars of today will run poorly and throw a fault code and or a check engine light for a lean condition simply by pulling out the oil dipstick on the engine and having it not seat properly. This again allows excess air into the system.

  • @DrummerDanVa
    @DrummerDanVa18 күн бұрын

    I got this code on a Mazda 5 less than two weeks after it had been serviced. I found something online and sure enough the tech must have opened the air filter housing to check it and didn't get the entire housing back in its proper place. After making sure everything was secure and clearing the code it has been fine. I check gas mileage every fillup and as long as the car is running fine these codes can be bullsh*t. Another money grab to get you to come in to pay $150 for the dealer to read the codes.

  • @williamplatt6859
    @williamplatt68592 жыл бұрын

    The sensors can be cleaned but, if that doesn’t do the trick, a new sensor or sensors will fix.

  • @chrisalarcon7013
    @chrisalarcon70134 жыл бұрын

    nice vid and the gorgeous girl was a nice touch as well

  • @fixdapp

    @fixdapp

    4 жыл бұрын

    Glad you enjoyed it!

  • @plainoldme7322
    @plainoldme73224 жыл бұрын

    I am willing to bet my code happens when I use at least a half tank of E85 gas and my truck is not designed to use it

  • @CatMan81
    @CatMan812 жыл бұрын

    Or a bad purge valve.

  • @JasonSpitzMI50
    @JasonSpitzMI504 жыл бұрын

    OMG 😍 Where have you been all my life. I love a woman that knows something about a car 😍

  • @johnnydoggs
    @johnnydoggs5 жыл бұрын

    Yo honey good video

  • @teeti9401
    @teeti94015 жыл бұрын

    It looks nice to see a girl in the field of Mechanics. Nice presentation.

  • @edaguirre6723
    @edaguirre67233 жыл бұрын

    Hi my name is edy babe