How to repair fault code P0171 and reset warning light Toyota Corolla VVT-i. Years 2000 to 2019

How to repair and fix fault or error code P0171 and reset warning light Toyota Corolla VVT-i engine. Years 2000 to 2019. Air flow sensor needs to be clean totally, look how to do that. Also how to find fault code using OBD scanner.

[@CMW150]

I've watched several of your videos for tips and repairs for my 2007 Toyota Corolla. It has 205,00+ miles and runs great. Thank you for your help. I learn something new each time I was one of your "how to" videos, Curtis Wall The Colony, Texas

[@PeterFinnTheCarDoctor]

Thank You! :-)

[@083rt]

Thats 👏🏽 awesome , do you still own your Toyota? And how many miles does it have now? I recently purchased one for a good price its also in its 200,000+ miles.

[@0Acacia22]

I have this code error on my 2004 toyota corolla. Watched your vid and to tell the truth, i enjoyed your calm voice more than anything, sort of relaxing lol. Great info. though. thank you

[@PeterFinnTheCarDoctor]

Thank You Sir.

[@charliegone1652]

I did this as well with my Corolla, but the light ended up coming back. So took it to the mechanic and they did a smoke test. They found a cracked intake boot. Had to replace it, but also found the o2 sensor was faulty. So in the end it was a combination of stuff. Always good to be thorough. Check for leaks and test the sensors.

[@ngshein]

Step-by-step approach to PO171 issue in detail makes us more realistic. The way you sound English makes us more fantastic toward this viewing. Thank you for your diligence and kindness in sharing your experience with all of us.

[@PeterFinnTheCarDoctor]

Hi and Thanks for your comment. :-)

[@missusladypants]

Followed this video and fixed the problem! The light was on for years and many sleazy mechanics "fixed" it (it went back on within days). The secret is, they were cleaning and putting on the same worn out MAF sensor and not realizing it was worn out. We bought a new OEM Toyota sensor (yes, it was $115 bucks, but we had spent way more to have it reset over and over). Anyway, this is an EASY fix. 2 screws and you're done. Thanks Peter! My only complaint is that you cut out the part of the video where you say "Hello Toyota Friends!" Hubby and I said that the whole time we were fixing the car…which was not long.

[@PeterFinnTheCarDoctor]

Thanks. :-)

[@hausimports9858]

you are amazing thank you for the very well and calm lesson , God bless...

[@nicolec.6303]

Thank you very helpful video only one on KZbin that explains everything perfectly thank you

[@PeterFinnTheCarDoctor]

Good. 😃👍

[@fahadsheikh5374]

Thank you Mr Peter ! that is very good explanation with Practical and giving very useful Information n again THANKS !

[@PeterFinnTheCarDoctor]

Thank You too and You are welcome. :-)

[@chrislopezs5265]

Thank you you saved me lots of money over $ 175.00 dollars

[@17rink]

Thanks Peter for sharing this video...i cleaned my car's oxygen sensor and after resetting battery,engine light went off

[@PeterFinnTheCarDoctor]

17rink Thank You very much for comment.

[@YamahaC7SRG]

Hi! Excellent video. Thank you so much for taking the time to make it. This is one of the best videos I've ever seen on car repairs! I hope you make more videos and have a nice day! Thanks again!

[@PeterFinnTheCarDoctor]

YamahaC7SRG Thanks for comment.

[@planetsavers5909]

Thank you for sharing your knowledge.Your amazing

[@PeterFinnTheCarDoctor]

Thank You for comment. :-)

[@KLM817]

Good information. You can also reset the check engine light with your OBD scan tool as well.

[@PeterFinnTheCarDoctor]

KLM817 Thank You. I appreciate your feedback.

[@shawneeguyman79]

Thank you for your time making videos.

[@joesmania]

Thank you for sharing your knowledge.. You'd make a great teacher. You showed & explained very well with great details...

[@PeterFinnTheCarDoctor]

Thanks Sir. 👍

[@carlosperez-abascal6799]

thanks for the video it really helps thanks so much

[@PeterFinnTheCarDoctor]

carlos perez-abascal Thank You very much for comment.

[@carlos92161]

Thanks mr peter great job!!

[@PeterFinnTheCarDoctor]

Thanks for comment.

[@ghjj43]

worked perfectly ! thanks.

[@PeterFinnTheCarDoctor]

Thank You. :-)

[@mcmasti]

Nicely done -- very clear!

[@PeterFinnTheCarDoctor]

+mcmasti Thank You. :-)

[@mohammadaljober864]

thanks Peter Finn , very good u tube if we have rich situation not lean witch sensors defects.

[@PeterFinnTheCarDoctor]

Thanks for your comment. :-)

[@stsfnaf.613]

Really good tutorial not sure it will help to fix my car

[@PeterFinnTheCarDoctor]

Hello and Thanks Sir for feedback. :-)

[@pinkiero]

Hello Peter, i have a RAV 4 2006 3.5 L engine, what happens when you have the code P0174 code coming up with P0171?

[@thomassamuel6889]

Thank you for sharing this video Peter. I also own a 2000 Corolla in average good shape. One issue I have I don't get enough milage. Can give some advise. Recently I changed my catalytic converter (universal brand). Check engine light has gone after that. If I clean MAF sensor will help. Please help.

[@PeterFinnTheCarDoctor]

+THOMAS SAMUEL Hello, those non originals catalytic converters (universal brand) use is not so good idea. They last short time. Maybe also your cars catalytic converter is now damaged too. Please do also this test or if issue is still on visit the Toyota delaer center. Look these videos: kzbin.info/www/bejne/nIaYn2CMfbV0eqM and kzbin.info/www/bejne/g5W9hoN-ltiqpNE

[@KrisCortez]

If you're facing the dreaded P0171 CEL code on your Corolla, and you've already replaced the intake manifold gasket and cleaned or replaced the MAF, but the light still won't go off, it might be time to bid farewell to your ride. Unless you're willing to dive deeper into the rabbit hole with some serious DIY skills and spare cash for parts, it's probably not worth the hassle. Trust me, and others who have been down this road before, you could end up replacing a ton of parts and still not get rid of that pesky code. So, be cautious and consider your options carefully!

[@PeterFinnTheCarDoctor]

I have read your message, Thank you 😀👍

[@rvhflvcko5016]

My car has this code (1999 Toyota Camry) it was hesitating at first when I accelerated for a few weeks and now it doesn't move foward at all. I had a terrible leak in my flex pipe but I've fixed that problem. What do I do now ? My car reverses but doesn't do anything when I hit the gas

[@PeterFinnTheCarDoctor]

Hi, sounds like you have many issues... Could you take video and send video link to me?

[@nicorome7154]

use only mass airflow sensor cleaner / do not touch the sensor because it is very sensitive

[@PeterFinnTheCarDoctor]

Ok

[@samuelescobar2479]

Thanks you for your video is very helpful for me.

[@17rink]

Thanks Peter for sharing this video..it helped me to clear engine light

[@PeterFinnTheCarDoctor]

17rink Good and Thank You very much for comment.

[@nonewhy6658]

wow rpm 1100 and the trouble in fix nice job

[@blessakpo7886]

Please I need I help on my Toyota corolla 2010 which can't accelerate when I step on the paddle

[@abpccpba]

Peter I have been told that carburetor cleaner will leave a bad residue;nor good. You should use cleaner specific to air flow meter.

[@PeterFinnTheCarDoctor]

Paul C Johnson Hello, this my cleaner worked 100% and I fixed my P0171 issue. I can recommend always Valvoline products and like that carburetor cleaner to clean air flow sensor in Toyota.

[@mukhtarbegum3633]

Peter Finn i also have the same problem

[@stevenpappas8138]

Carb cleaner is a solvent and leaves no residue, It evaporates very quickly and costs much less than mass air flow sensor cleaner.

[@thomasszeles634]

Great video!

[@PeterFinnTheCarDoctor]

Thanks. :-)

[@LuisDanielMatias]

I did exactly the same. Removed and cleaned the sensor with carburetor cleaner; however, the code comes back again. Corolla S 2007. What do you suggest? Thanks BTW Nice video

[@sargonkhabeer8471]

Help plz. 2005 Corolla with p0171. So far have changed the maf with Toyota oem part. Replaced both o2 sensors with denso. Changed intake gasket. Changed catalytic converter due to a leak. Fuel pressure reads at 49 psi. Removed and cleaned fuel injectors. No vacuum leak. Car running very rough at idle. At idle, short term fuel at 0 and long at 25. At 2000 rpm, short at -4 and long jumps to 40. Any ideas plz.

[@PeterFinnTheCarDoctor]

Yeah, please measure your engines compression rates. What are results. Look info video: kzbin.info/www/bejne/eKqqaH-cZbd3p6c

[@thenat4658]

the engine light came back on again with the same code. Is there another sensor I should clean? I was told by the lady at the auto store that it could be my catalytic converter being clogged. help...thanx!

[@PeterFinnTheCarDoctor]

Hi, there are other sensor and issue areas too. What car and code You have?

[@juanmarte1595]

Hey Peter, thanks for the videos I watch most of them now as a 2000 Toyota corolla owner. I recently had the p0171 error come up. I installed a new air flow sensor and i reset the engine light, but it came up again. When i turn on the car it is really slow to start i need to hold key tuned for longer than normal. Are there other issues that are associated with p0171? If so, any videos for how to fix them?

[@PeterFinnTheCarDoctor]

Juan Marte Hello. Yes. Please check also next things:- Intake air leaks - Faulty front heated oxygen sensor - Ignition misfiring = spark plugs and coils - Faulty fuel injectors - Exhaust gas leaks - Incorrect fuel pressure = fuel pump - Lack of fuel = fuel pipe leaks - Faulty Mass Air Flow (MAF) sensor - Incorrect Positive Crankcase Ventilation (PCV) hose connectio

[@melissashaw8370]

I Did the smoke test and fixed the leakes and all hoses. Code was still on. I changed the o2 sensor and same code. My cpu (computer) was bad so that was changed as well. Same code reset everything. Then I changed the Fuel pump. I have a 2005 Toyota Camry. Not sure what to do. Tomorrow im going to try to clean the the throttle body. (Any other suggestion to fix issue?)

[@PeterFinnTheCarDoctor]

Hi, do you have oil consume ?

[@melissashaw8370]

@@PeterFinnTheCarDoctor my short fuel trim was reading -1.6(%) and my long fuel trim is reading 36.7 (%). I cleaned the throttle body and got a better reading. Drove around and and everything set to smog the cat and 02 sensor was finally ready but still pending the same code P0171 then the check engine light came back on again but everything was green on code reader. Someone said my fuel injectors may be bad.

[@yozgatlicaner]

p0171 is multiple problems the worst code ever !!!! o2 sensors ?!! either fuel line or air vacuum issues or even related p0300 misfire change your coils spark plugs check the wires fuel injectors maf sensor or fuel injectors or even fuel pump or fuel filter. You r welcome guys :)))

[@PeterFinnTheCarDoctor]

+yozgatlicaner Hello. Do you have Toyota or some other car? In Toyota, there is no many issues in same time.

[@yozgatlicaner]

+Peter Finn I have vw passat but it doesn't really matter what kind of car you have once the car gives you p0171 code you are already in trouble there is to many codes hidden behind that code once you fix the issue it will give you different codes best way to fix check your pcv valve first check your vacuum leaks smoke test os the best way to find the leak if no leak check your maf if sensor is broken replace it change your o2 sensor in the rear check your spark plugs and coils fuel lines.

[@PeterFinnTheCarDoctor]

Ok, I thought also, that you should have a different car then Toyota. :-) And I am also old old VW man..., I know VW quality.

[@TomSommer]

+yozgatlicaner The problem is its a VW. get rid of it. Cut your losses.

[@tonycavez]

facofe my vw has 276000 and i'll drive it cross country right now

[@rjben1993]

I have a 96 honda dx...I'm getting a po171 code. the car engines shuts off while driving, but I'm able to push the clutch in and it starts back up immediately...help?

[@PeterFinnTheCarDoctor]

Hello, the Honda is new to me. I need to do research...

[@skeeter2112]

Could be the intake manifold gasket. Just did mine. Part less than 20 bucks but all labor. Still got done for $160. Bad gasket could be letting air into engine making the fuel mixture too lean. Being that old gasket is probably not in good shape and replacing will only help.

[@girohead]

It's nice having an older car with tons of parts available and most questions were already answered by Peter! I have carb cleaner and brakecleaner and figured either would be okay but I thought I saw another video say only use MAF cleaner - sees like a lot to do once in a long while. I use a reuseable oiled Fram filter and wonder if that gunks my MAF sensor? I don't over oil it, this was first PO171 anyway.

[@girohead]

Cleaned MAF as shown, after cleaning filter, and code came back on, PO171, will try again.

[@stephenjackson4392]

I have a Honda Civic. I used the correct cleaner cleaning my MAP sensor and it acttually damaged the sensor and it made it worse. I had to buy a brand new sensor to fix the idle issue

[@nilsona6983]

What OBD2 scanner brand did you used?

[@PeterFinnTheCarDoctor]

Torque is program and I have Android Samsung cellphone.

[@tabtab5768]

one moor thing peter my battery light is on i have change a new battery but still on. looking for some help please . cheers

[@PeterFinnTheCarDoctor]

tabtab5768 Hello, you might have issues in alternator. Please look my video:kzbin.info/www/bejne/Z2HNZqujoZunnrc

[@iddyhasani5603]

Thank my technician for good adiea

[@PeterFinnTheCarDoctor]

Hi and Thanks for feedback. :-)

[@tteuvky]

21:25 What is that air line that you just popout to and plug in vaccum meter? i mean what is his purpose what it do exactly?

[@bigmanaguilar2299]

thanks 4 this video

[@PeterFinnTheCarDoctor]

+big man aguilar Thank You. I appreciate Your feedback.

[@tardeliesmagic]

While you have your bonnet/hood up do your PCV valve and throttle body too

[@PeterFinnTheCarDoctor]

Yes

[@michaelchang4391]

Most toyota but not all model, inside air flow 2 sensor section cleaning is important.

[@PeterFinnTheCarDoctor]

Thanks for comment. :-)

[@mosthated8190]

I have a P0171 that goes away and comes back. I’ve replaced intake manifold gasket , exhaust manifold and gasket, MAF sensor , and a few hoses. And still dealing with this issue. I’m gonna purchase a smoke machine and try to diagnose it myself.

[@PeterFinnTheCarDoctor]

Commenting on this video is FREE, but if you have technical questions for me, I charge a small fee for answering them, normally 5 USD $ per question. I am a true Technical Professional, Black Belt in engineering and The Car Doctor! Enjoy and ask. I'll answer professionally. So, if you have question: You pay 5 USD $ via the THANKS button below the video to me. Add user your name to text line. Make the payment and I will then give you a professional answer.

[@THR36IX]

what year is your corolla. my 04 corolla injector gaskets were causing my p0171 as well as misfire on all cylinders. was a really easy fix

[@bdsmartypants77]

Mines 2006 any vid you’d recommend to help change the injector gaskets as easy as you did it?

[@kumard1926]

Hello sir camry 2010 model automatic transmission vehicle starting time idle running RPM is below 900 to 700. forward gear or reverse gear changing time RPM is 400 to 500. what is the problem on this vehicle?. please tell me sir

[@PeterFinnTheCarDoctor]

Hi, this is normal is Camry engine.

[@robertovasquez5139]

100 % EXELENT

[@PeterFinnTheCarDoctor]

Thank You for feedback. :-)

[@williamsolano2571]

Cool 😎 video bro.👍🏻🙏

[@ReclusiveMountainMan]

Carb cleaner is too harsh for MAFSs. Compressed air isn't a good idea, either. You can get sensor cleaner, and you're suppose to let air dry. You don't want to damage the sensor. Pressurized air and harsh chemicals can cause damage to the MAFS and the surrounding plastic. Also, why do you have what looks to be RTV around the MAFS? Is the grommet, o-ring, or housing cracked? That could also cause your code.

[@PeterFinnTheCarDoctor]

***** Hello. My sensor is now OK and now any issues now. And Carb cleaner worked OK and also compressed air. Toyota parts are hard stuff and they don't damage easily, like with compressed air handle.

[@nguyentra7580]

+Peter Finn Hey Peter. Thank you for your video. But in case that I dont want to use the Carb cleaner to clean the sensor, what should i use ? Water ? Please help i also got code P0171 too. And the dealer want me to replace the ECM with the price over $400.

[@thenat4658]

I hope this fixes my engine code...thank you.

[@PeterFinnTheCarDoctor]

Hi and many Thanks for comment. :-)

[@thenat4658]

it worked...the light is no longer on and performance is the best it has been for almost a year. again, thanx!

[@mg6775]

hey did that come back on?

[@electronic7979]

Excellent

[@PeterFinnTheCarDoctor]

Thanks. :-)

[@rodrigohir1]

It´s the VVTi idle engine rpm 900?

[@PeterFinnTheCarDoctor]

Rodrigo Soma Yes. Sir.

[@rodrigohir1]

Thanks

[@ekramulhaque1861]

I Cleaned Air flow sensor steel same fault error code P0171, then I put new Air flow sensor steel same fault error code P0171, what can i do now?

[@PeterFinnTheCarDoctor]

Hi, what car You have?

[@ekramulhaque281]

Toyota corolla ve 2000

[@PeterFinnTheCarDoctor]

Hello. There could be issues in these areas too: - Intake air leaks - Faulty front heated oxygen sensor - Ignition misfiring - Faulty fuel injectors - Exhaust gas leaks - Incorrect fuel pressure - Lack of fuel - Faulty Mass Air Flow (MAF) sensor - Incorrect Positive Crankcase Ventilation (PCV) hose connection

[@1uP-v2]

Thanks

[@PeterFinnTheCarDoctor]

You are Welcome, :-)

[@tabtab5768]

can i clean withe a w40 peter ?

[@PeterFinnTheCarDoctor]

tabtab5768 That works also, but cleaner is better.

[@beexiong2171]

i tried this today i hope it works and keep the pesky engine light off

[@PeterFinnTheCarDoctor]

Good comment. If you want more help from me, then become a member of my channel. 😀👍

[@zainabadamu6125]

Good afternoon sir, please my problem is this. I have this exactly scanner (roadi) but the cable is bad. So please how do i get one?

[@PeterFinnTheCarDoctor]

Commenting on this video is FREE, but if you have technical questions for me, I charge a small fee for answering them, normally 5 USD $ per question. I am a true Technical Professional, Black Belt in engineering and The Car Doctor! Enjoy and ask. I'll answer professionally. So, if you have question: You pay 5 USD $ via the THANKS button below the video to me. Add user your name to text line. Make the payment and I will then give you a professional answer.

[@margaretborsbey1193]

this code can also show as PO170. thanks.

[@PeterFinnTheCarDoctor]

+margaret borsbey Thanks !

[@raulernestomartinezventura5175]

Es el empaque del multiple es el que se daña no es el sensor.. Gaskets

[@PeterFinnTheCarDoctor]

Thanks.

[@raulernestomartinezventura5175]

👌

[@zk4707]

Can we use WD40 to clean this sensor??

[@PeterFinnTheCarDoctor]

No, please use carburetor cleaner.

[@AftabAli-qp2qr]

I even changed the o2 sensor the map sensor can’t see any leaks but still got lean code.

[@PeterFinnTheCarDoctor]

Noted 👍

[@tabtab5768]

thanks peter

[@PeterFinnTheCarDoctor]

tabtab5768 You are welcome.

[@puteribanjar4382]

Hey hey, the best info that i have seen was on Volt Daddy (just google it) Gotta be the most informative info on batteries and this same things that i have found.

[@PeterFinnTheCarDoctor]

+puteri banjar Thanks for feedback. :-)

[@shaukatalishaukt5478]

My car problem open fuel tank cap engine stop corolla 2015 after a long time start

[@PeterFinnTheCarDoctor]

Really.

[@clayton4115]

had the code on my camry, turns out it was dirty fuel injectors

[@PeterFinnTheCarDoctor]

Hi and Thanks for Your comment. :-)

[@clayton4115]

it took me 9mths to work it out, hopefully it will help someone else

[@Acosta-on7do]

Did you replace them? Or is there a way to fix them?

[@Alfaraj777]

what name of this sensor!

[@PeterFinnTheCarDoctor]

MAF SENSOR

[@Alfaraj777]

thank you :)

[@luisalegria4428]

sensor maf?

[@PeterFinnTheCarDoctor]

+Luis Alegria Yes

[@JOEWOLCHAK1]

Me again; That eng light fix is only temporary, mine came back on after 1/2 an hr city driving. The vids I recommended did a live data monitor of f-injectors, then O2Sensor, and LTFT ( long & short f-trims ). don't replace 02S before checking injectors, which a miss can contaminate it. In the vid, they finally replaced injector & 02S. As to the PO420, don't replace expensive converter, but only after checking and fixing probs in front of it first. ( sensor & injectors ? ) BTW, What make / model is that scanner with live data and @ what price ? Please reply, [e-mail]

[@colinlawrence8313]

but you did not spray the airflow sensor (the thin coil of wire down inside!)!; just the thermistor that measures temperature 😟

[@PeterFinnTheCarDoctor]

Noted

[@marxseet]

Cleaned my air flow sensor, but the P0171 still come out

[@PeterFinnTheCarDoctor]

Hi, here: Intake air leaks, Faulty front heated oxygen sensor, Ignition misfiring, Faulty fuel injectors, Exhaust gas leaks, Incorrect fuel pressure, Lack of fuel, Faulty Mass Air Flow (MAF) sensor, Incorrect Positive Crankcase Ventilation (PCV) hose connection

[@DougHNuts-ee3vn]

Best to play it safe...sure carb cleaner will work but later on down the road, it may cause damage to the o-rings and what not on the MAF. They sell a MAF cleaner like CNC MAF cleaner at local automotive shops. It looks like this if anyone is curious. shop.advanceautoparts.com/p/crc-mass-air-flow-sensor-cleaner-11-wt-oz-05110/7070079-P Product Features:Plastic safeSafe on sensitive equipmentIncreases horsepowerReduces rough idleDecreases hesitation and pingingImproves fuel economy MPGEntire job takes less than 10 Minutes

[@PeterFinnTheCarDoctor]

Ok

[@colinlawrence8313]

sorry did not watch all of video you did then notice the most important part that senses air speed ( the thin wire is heated and it's resistance changes with air flow that the ECU uses to adjusts fuel flow😁

[@PeterFinnTheCarDoctor]

Noted

[@Nick-co1bj]

Please do not clean your MAF sensor carb cleaner or WD-40. Your car will thank you

[@PeterFinnTheCarDoctor]

Hi and Thanks for comment. :-)

[@raufkakar7593]

Use Miss air flow sensor spray

[@PeterFinnTheCarDoctor]

Good comment 👍

[@stevenpappas8138]

Do not buy off brand sensors, such as mass air flow or o2 sensors. Many sold on ebay are junk. I put an off brand o2 sensor on a Honda and immediately the check engine came back on.

[@PeterFinnTheCarDoctor]

Good comment and Thanks ! 😀👍

[@HulkSmash563]

Great video if I could understand your English... :(

[@delgernaranb5720]

your English is so Funny. cant watch it cos i am still smiling

[@PeterFinnTheCarDoctor]

Thank You for feedback. :-)

[@cabr0nf1b3r]

Dude you gave me anxiety watching you use a pick to clean the fine wire element of the MAF. You never touch the filament and you only use MAF sensor cleaner otherwise you can damage the internal circuitry of the sensor.

[@ATL3xtra]

carb cleaner for a MASS AIR FLOW SENSOR?? yikes... Use a Mass air flow sensor cleaner, those are very sensitive

[@PeterFinnTheCarDoctor]

Yeah !

[@vincelee2658]

ATL3xtra ㅍ

[@andrewg8288]

hey Peter you to much bla bla no action

[@PeterFinnTheCarDoctor]

Hi and Thanks for feedback. :-)

[@deriklfixit]

@@PeterFinnTheCarDoctor don't listen to him Peter, be how you are.

[@dno8494]

🤮

[@SuperSteeler98]

I really wish it was easier to understand you. You need some English lessons.

[@PeterFinnTheCarDoctor]

Thanks ! You are Welcome too. :-)