Need Help! Check Engine Light, Pulling code P0171

[RobPA]

Hey everyone! Having a problem with a friends 02 WRX. She is pulling an errorcode P0171. Which means a lean condition in bank 1 i believe. The car in the lower rpms seems to also be running a bit rich to compensate. Besides Cleaning all 02 Sensors, any idea how to fix this problem? The car is obviously out of warranty and we are trying to fix this in the most affordible way possible, so anyone who can give me any tips please help!

[SD_GR]

She is pulling an errorcode P0171. Which means a lean condition in bank 1 i believe.

There is only 1 bank.

Besides Cleaning all 02 Sensors, any idea how to fix this problem?

Assuming fully stock car: Check airbox for leaks, check for vacuum leaks, clean MAF, clean MAF again, check air filter itself, check tubing to fuel pressure regulator. If the car is not stock things get more complicated.

[RobPA]

There is only 1 bank.



Assuming fully stock car: Check airbox for leaks, check for vacuum leaks, clean MAF, clean MAF again, check air filter itself, check tubing to fuel pressure regulator. If the car is not stock things get more complicated.

Car is stock except for catback (obviously not gonna throw that CEL) Cleaned MAF, Checked tubing TO FPR, no krimps etc etc. Air filter was cleaned but seem to be cleaned slightly improperly. Car only gets up to .07 bar which I know is closed to max stock booste. Car still feels really hesistant. Reset the computer and it took 24.7miles for the CEL to come back on. Any other ideas? Im willing to try anything, thanks!

[SD_GR]

A faulty O2 sensor, albeit a clean one, is one guess.