Hi all,

I have a 2000 Sunfire with the 2.2 LT engine and 3 speed automatic. It has give me a code (171) indicating that it is lean in bank one. The car runs great most of the time. However when I stop at a light the engine starts idle rough. When I take off the engine seems to lag and then it will surge. It does not do this all the time. Anyone have any thoughts on what could be causing this? Any help is greatly appreciated! I am going to replace the PCV valve tomorrow.

Thx,

Nevada

Sounds to me you got a problem with youre O2 sensor, Try replacing it, See if that corrects the problem, Also I would take a close look at youre wiring harness as well, For Shorts or breaks in the wiring.

Good Luck.

P0171 System too lean bank 1

Obviously ignore the part about the MAF. Look for vacuum leaks; your rough idle, lag'n surge are definitely symptoms of a vacuum leak, but can also be caused by other things. But do the leak check first, since its free. Then move on to the fuel filter and possibly replace that.