2003-2013 Toyota Corolla P0171 Fix

[@stanislavdidenko8436]

It worked! The code disappeared even with no scanner after 2-3 rides. Thank YOU!!!!!!

[@FreedomofSpeech865]

Thank you, this was easy to follow for a woman with zero confidence in taking care of a vehicle

[@MarzNet256]

Cool. These 1ZZ-FE engines also commonly develop vacuum leaks at the intake manifold gasket, which is easy to replace. You will experience rough idle, especially at colder temp, often there will be no lean codes until it get pretty bad. My 2006 Corolla Matrix has 200,551 miles and runs great.

[@techten1012]

Good for you brotha

[@jammin1881]

I just had this happen to my Pontiac vibe. The manifold gasket was flat and has no edge or raised lip. Replacing it has given back a smooth idle and the light doesn't come on. Engine code po1717 and lean condition on bank 1. Buy the genuine Toyota gaskets for about 12-15 bucks .

[@leof7635]

Yes try to clean the mass air flow sensor and just look and see if there is any air leaks like cracked vacume lines that the first steps

[@utube5361]

U should put it upright when u spray it so the cleaner doesn't come inside the electronic

[@robertsimpson7113]

Sometimes its a bad intake manifold gasket (seal) creating an air leak and subsequent code P0171

[@leof7635]

Yes of course that could be true

[@marggiomusica]

Thank you bu your help. From California

[@seanevans7471]

Read the back of the can, most maf sensor cleaners say right on the can not to use for toyota or Lexus applications.

[@mannyroias3392]

Make sure it has the orange intake manifold gasket! Its usually the gasket that has gone bad.

[@GregariousAntithesis]

All the issues you describe would lead to a rich mixture not a lean mixture like a dirty air filter.

[@666norouz]

P0171 means " System too lean bank 1" . What test/tests did you run to figure it was MAF sensor ? There are other components that will give you the same DTC code . For example AIR LEAKAGE, faulty fuel pump, low fuel pressure , faulty throttle body actuator , to name the few .

[@Youworstnightmare77]

Exactly ist not just cleaning the air mass flow sensor I ha ve the same code problem for 4 years and in all those years I change 2 times both oxygen sensors 4 times the sparks plugs new coils 1 time the fuel injectors and mi last repair was the manifold gasket to try pass the smog check and nothing. and all that I have. Changed because the same code p0171 keeps appearing for the last 3 and a half years and I have not solved that problem. What will it be, I couldn't tell you and just as you say without several factors. It is nothing more than cleaning the mass air flow sensor and that will solve it. And sell have the same code..🤷🏻

[@trewten5579]

@@Youworstnightmare77 I feel you! I've replace the pcv valve, pcv hose, MAF sensor, ignition coils, fixed all vacuum leaks, cleaned injectors, and still same code!!

[@artpatronforever]

@@trewten5579 Fuel starvation can also cause P0171 due to dirty pickup strainer usually from rust, tired fuel pump, dirty in tank filter cartridge, or fuel pressure regulator, all of which should be replaced at 10 years or 100,000 miles as routine replacement. That service was just done for the second time by me on a 2001 Corolla with 218,000 miles and a half cupful of rust dust was siphoned from the fuel tank well at each servicing, as a testimonial about the use of ethanol blended gasoline which attracts moisture and causes the observed problem of rusting fuel tanks with all the collateral effects on pickup strainer, fuel pumps, filters, and fuel pressure regulators. Downstream from the MAF sensor a vacuum leak can also cause the code. A dirty air filter is not going to cause a too lean condition but would make the mixture too rich. A gradually worsening throttle response with the P0171 points strongly to fuel starvation with a dirty fuel filter as a prime suspect, but sensors or vacuum leaks can also cause the code. So it is a go down the list scenario to sort out and identify the exact cause.

[@jeffdouglas5325]

Did this fix the issue or did you need to replace the intake gasket? Thanks

[@leof7635]

Hello it worked on this car but this is something you can try first if you have a cleaner also yes these cars are known for intake gasket if you click my other video you will see how I changed the gasket it's not that hard

[@jammin1881]

Spray carb cleaner over the area of the manifold gasket. It will change noises or the revs will be noticably different. If the engine revs harder after you spray. It's the gasket needing replacement. It's sucking in air and causing a vaccum leak.

[@bigmike2149]

So no checking ST and LT fuel trim??

[@errfonn]

Make a video on shafts crank sensor plz

[@RusliAbuBakar-q8t]

Helo Friend ,what kind of scanner u are using,can u describe detail of scanner,I want to have one,tq

[@alexwesley9863]

It has to be mass air flow senser cleaner or it will gobad later.

[@enriqueatala2567]

Hello, thanks for your video. One question, I have a 2008 Toyota Corolla with 230,000 km of manual gearbox, 1.8-liter engine, type 1ZZ-FE. The fault is that when you turn it on it starts with 1300 rpm and as it warms up it goes up to 2000, that is, it does the opposite since I understand it should go down to about 900 rpm. and when I'm hot I go out and when I make the gear changes I see that the rpm's go up and down between 2000 and 1000 rpm's and when I keep going the minimum is 2000 rpm. If I leave it running stopped the car stays at 2000 rpm's. I clarify that with the Toyota scanner it did not give an error, that is, the check engine does not turn on. Well we took out the carburetor, total cleaning including the MAF sensor of the filter, I clarify that you cannot remove the IAC valve to clean it because it has a key that I do not know and I think it is a pentalobe, but the carburetor body was submerged in non-abrasive remover liquids and it came out a lot of dirt I guess carbon. We measured TPS and IAC with a multimeter, simulated with power and everything was fine. We checked the pipes that had never been touched and were spotless. We put everything together and it starts doing the same fault. Then I disconnected the EGR vacuum valve and there the rpm's dropped a little but after five seconds it accelerates and when I connect the hose, it returns to 2000 rpm. The same if I disconnect the PCV valve and it idles from 300 to 500 rpm's, almost stopping, but it continues to oscillate from 300 to 500 rpm's. Take out the PCV valve and replace it with original and the problem continues. I took out the intake manifold, towards one end I saw oil and dirt in general, everything was cleaned, I saw a deformation in the plastic gasket and I sealed it with plastic insulating tape and changed the manifold gasket for the original one (as I saw in your video ). Put it together and continue to fail, remove the PCV hose and the engine drops in rpm's but drops to 200 rpm and tends to stall. I also removed the EGR valve and the engine lowers the rpm's a little but immediately accelerates more. Could it be a fault with the EGR vacuum valve or injectors or coils? I clarify that the engine at high does not fail or smoke. I am disoriented since the scanner, of the original Toyota brand, does not give an error and the Check Engine light does not turn on either.

[@forhisglory700]

Thanks so much, very helpful.

[@enriqueatala2567]

Hello, thanks for your video, two queries, one is with what brand and model of scanner did you use to find the P0171 fault?

[@leof7635]

Hey hello you don't need any specific scanner just a basic obd2 scanner will do the trick you can puck one up cheap on Amazon

[@keving52002]

Good video. So a bad or dirty MAF sensor can go bad without throwing a code?

[@leof7635]

Yes I've seen that befor that it doesn't throw a code and you will need a more specific code scanner to see the values in live mode

[@Dj-ve2hx]

No , too much air, or not enough fuel .

[@eliezerramosjr1017]

This is what you don’t wanna do guessing is not the way test it.

[@leof7635]

This was not a guess simply cleaning the mass airflow from a lean condition is a simple way to save you thousands thank you

[@TehKaiser]

​@@leof7635MAF is usually a minor or insignificant cause.

[@johnnynewburgh9745]

tryed cleaning did not work. Installed new sensor worked no code. Also had small evap leak after changing fuel pump could not get evap line back on correctly. There is rubber o ring and plastic ring was not paying attension when they came out of evap hose. so i did not know if plastic ring or oring went into hose first. after trying several times i relized plastic ring goes in first but you need to use handle of screw driver or something to push into hose and then it will click in then it is back far enough to install oring . Man that drove me nuts and could not find info on it ......good luck to all,,,I beat two codes Boo Ya

[@WV591]

if only it were this ez in real life.

[@Autofixgarage-ng]

Tot system to lean is simply too much air in the engine.

[@md.azwadulhaque3900]

i have the same problem on my toyota vitz 1.0l 2009 model, any suggestion?

[@luisematos_]

Check air filter, sparkplug calibration, ignition coils and MAF clean also the two resistors inside of the sensor. I has the same inconveniente and it fix it 👍🏻

[@eliezerramosjr1017]

Yes test not guess like this guy.

[@TehKaiser]

Make sure gaskets on intake are good, injectors are clean, coils are good.

[@Martin911]

Dude won’t even show the short and long throws readings before and after repairs. Smh,

[@grandtheftauto1233]

Yeah dude what a waste of

[@WilbertSteffy]

This is similar to checking the fuses…. Start with the simplest sometimes. Not everytime. Not entirely a waste, a lot of people neglect the air filtration and end up with dirty mass air flows. Some basic scanners don’t have live data.

[@grandtheftauto1233]

@@WilbertSteffyelm327 cheap scanners easily can show data graphs (free apps) Basically showing the readings would help in diagnoses

[@eliezerramosjr1017]

As a master tech this guy is just loaded the parts cannon. 🤦🏾 Don’t let him near your vehicle or you’ll be couple grand in the hole.

[@SubdolphinX]

Don't think that facemask was catching enough spray.

[@angsieverz4938]

When an electronic component is failing, it behaves INTERMITTENT, the maf is an electronic piece, 2 sensors, resistors. It communicates wrong info to computer, and that's it. Since it's the inexpensive, easily accessible, you may want to start there, the least suspect. No amount of Spraying rectifies a failing electronic part.