gr8twhite

iTrader: (1)

P0171
Fuel System Lean (Bank 1)

What would cause this , a bad O2 sencer.

Rhino79

iTrader: (7)

That is what it sounds like to me.

budhayes3

iTrader: (19)

Could be the bank1 O2 sensor, an exhaust leak allowing air to enter the exhaust giving the sensor in incorrect reading, vacuum leak on bank1...there's a few things that'll throw that code. Believe it or not, that de-screened maf that's in your sig could even contribute to this code. (we see this code at Lexus all the time, and 9 times out of 10 it's a bad maf sensor...can't really compare Lex and GM though...)