P0171 code won't go away!!!!!!

[Oldman]

Have had this problem and have posted several times. Driving me crazy. I have a P0171 code. Here's what I have done so far.
Replaced all vacuum lines. Smoked the engine and found no leaks after replacing vacuum lines.
Replaced fuel pump. Replaced fuel filter. Replaced MAF sensor.

Any ideas? I'm getting of this light being on and this code showing up. It's been 6 months!

Any ideas would be appreciated. What other symptoms would I see if I had a bad head gasket or bad LIM gasket. Since I only have the one code for bank 1, should that indicate that the other bank is fine?

Please help!!!

Thanks,

[justin85]

replace your O2 sensor, the one before the catylic convertor.

[Oldman]

Most other websites I've been to say that if the O2 sensor is bad it will cause a different code. They also say that the O2 sensor does not cause this code. Are you sure it might cause this code? Just hate to keep throwing money at this problem on things that don't correct the problem.

Thanks,

[Mechtech]

MAF can cause a p0171 with no vacuum leaks. Failed fuel injector. low fuel pressure. leaking brake booster. O2 sensor stuck lean.

Connect a scan tool watch short term fuel trim. Should show + numbers, pcm adding fuel. Try adding fuel like carb clean down a vacuum line. Fuel trim should show - number pcm taking away fuel. If fuel trim stays lean O2 sensor has gotten stupid and needs to go. You can use carb clean to look for vacuum leaks while watching fuel trim. Just be sure you have good ignition wires or you could light up your car.