Code PO171

[Mooseknuckle]

I'm gonna look at it this weekend and order the sensor,from what I hear its a pain to get to I wanna make sure I'm not taking the wrong thing apart. When I took the throttle body off to clean it it looked like some of the gasket or maybe some adhesive that was used when first installed came off and was on the back of the throttle body. Just wanted to make sure that I didnt need to re-aply to insure a good seal. I feel like an idiot,thanks for your help guys very much appreciated!

[Mooseknuckle]

Update I replaced the upstream o2 sensor,I purchased one from Napa for 63.00 and got a crows foot socket for 9 bucks at autozone, seems to be running better and the exhaust doesnt smell like something is burning. I'm in the middel of something else will give another update when I test drive.

[Diacom]

I just pulled a similar code off of my 09 GMC 2500hd, lost throttle response or rather when I accellerate and the vehicle downshifts it actually slows down.

Got home, cleared the code and went for a test drive and pulled a P0171 an P0174 Bank1 and Bank 2.

Really though all this did was more or less confirm what I figure to be a fuel pump going out. It's a work truck so I'll limp it in Monday and find out which mechanic they want it taken to for further diagnostics and repair.

Hopefully in your case it was just the O2 sensor and not something further.

[Mooseknuckle]

Yeah well another update,it sounds the same the egine light was off now its back on. Next thing to do is go to autozone clear the code then i guess try the maf sensor or just get a cold air intake and bypass it all together then if that doesnt do it im off to the fuel filter and pump..