o1A4

i have a giac chip and kn air filter: i got the code maybe 2-3 months after installation i do not know if it is connected to the problem.. the car is an 01 and has 58k miles

I get this code all the time p0171 lean fuel trim bank 1 if i remember correctly, i thought that meant that the first oxygen sensor was mal functioning and needed to be replaced, however i read somewhere that the mass air flow sensor is causing this problem??? does it just need to be cleaned...

thanks

JAFO

maf is one of them but O2 sensors generally cause rich rather than lean. i'd try some fuel injector cleaner first.

o1A4

is that o2 the first one coming off the cat. behind the turbo

Ritz

Another trick is to disconnect the MAF. The ECU will fall back to the throttle position sensor for input it normally gets from the MAF. If the problem goes away, that's a pretty good indication that the MAF is toast. That trick is really useful when you have fuel related drivability problems that "come and go."

Cheers,