P0171

[Crowbar911]

Ive been getting P0171 for a while now. It started to come on after I put on my sway bars, but im thinking that is simply coincidence.

"P0171 - System Too Lean (Bank 1)
Basically this means that an oxygen sensor in bank 1 detected a lean condition (too much oxygen in the exhaust). On V6/V8/V10 engines, Bank 1 is the side of the engine that has cylinder #1."

From google.

I have cleared the code via code reader and ecu reset(battery unplug).

I have no performance loss, and I may have a little less gas milage, but hard to tell with the winter gas switch.

I have checked that I do not have a leak after the MAF.
I have used a K&N oiled filter since I got the car at 10K miles.
I recently cleaned my maf, which was FILTHY. I used MAF cleaner.
I have noticed that twice I get the code directly after I fill up with gas.
The code is now coming up more and more frequent.


I took the car to my mechanic, because while I can clear the code, its just annoying knowing that something isnt right. His first suggestion is to replace the air filter with a simple fram non oiled OEM filter. While this seems wrong to me, I do trust my mechanic. Rather than replacing the MAF or an O2 sensor which would make him money, he suggests something that doesnt at first.

Amy other suggestions? I have a hunch that the problem may be my MAF. So im going to look for prices on that. Any suggestions on this or other possibilities?

Car has 82Kish miles.

[teppista881]

Lots of posts on this. Just search for p0171--the number 0, not the letter O.

[CJCride]

New MAF solved my P0171. Some have cleaned theirs w/success. Mine had 180,000Km's/110,000Mi's.

[tech8]

P0171 on the Corolla usually is the MAF.

[Woodyg]

some thoughts could be a maf, could also be a fuel presure issue,to high/to low. Do a fuel pressure test, key on and engine running, could be a vacuum leak (spray carb cleaner around waiting for the engine to rev)