P0171 Code On 2004 Corolla - Toyota Corolla, Chevy Prizm (1998-2008)

I have a 2004 Corrolla sport and the check enguine light came on and the code is P0171. I have been reading the old post and I have some questions about the check enguine code of P0171. It looks like my first step should be to clean the MAF sensor. Why not just buy a new one? Are they expensive?

Then I think the next thing to check is the intake manifold gasket but that seems a bit complicated for me.

Any other advice on what I should check. I would appreciate any easy things I can check.

Also, the guy at the auto parts store told me I should replace the oxygen sensor. Yet, I didn't see any posts on changing the oxygen sensor to fix the check enguine light.

Any information would be greatly appreciated.

If you still have the original intake manifold gasket, it most likely is leaking and causing your P0171 code. Replace with Toyota's revised orange silicone gasket # 17171-22060 (Victor Reinz # MS19590).

http://www.rockauto.com/catalog/x,carcode,1432915,parttype,5424,a

MAF/IAT sensor is easily cleaned. It is expensive and there should be no need to replace it.

What mileage are you at, and what maintenance has been done?

Thanks Dom!!! I will clean the MAF sensor with some carb cleaner. Any recommendations on what carb cleaner to use or does it not matter?

I need to build up some confidence to repace the manifold gasket. It looks like I have to take apart pieces of the enguine to pull this off, right?

To answer your question, I have 130,000 miles. At 100,000 miles I replaced the spark plugs, transmissin fluid, and coolant. I change the enguine air filter every year and oil every 5,000 miles.

Any carb cleaner works. Brake cleaner is also the same stuff, as I use.

No engine parts to remove. Just remove throttle body without disconnecting its coolant lines, and remove the intake manifold... This should help:

http://www.toyotanation.com/forum/132-9th-generation-2003-2008/410129-diy-2005-2008-corolla-matrix-pontiac-vibe-intake-gasket-replacement-pics.html

I ordered the gasket. I am going to give it a try. Thanks!