P0171

[mulletsrock101]

Hi,

2006 TB 120,000 4.2 4x4

Trucks throwing light for code P0171. I see no difference in performance at all. Only notice MPG decreased. No loss of power. One thing to note is at idle (only in drive) i hear and feel vibration coming from passenger side front (glove box area) it immediately goes away if shifted in neutral or park or raising rpms. I think this is just a bad motor mount and no impact on P0171 .... thoughts on solutions ?

 

[m.mcmillen]

For the lean code, I would check and make sure that your intake manifold bolts are tight. Over time, the rubber compresses and the bolts will loosen up a bit. Snug them all down (not too tight) and see if it helps.

 

[Mooseman]

Also check the throttle body bolts or while you're there, might as well clean it and reset the PCM by disconnecting the battery for 30 minutes (or pull the PCM fuses).
https://gmtnation.com/forums/threads/how-to-clean-your-throttle-body.10607/

 

[djthumper]

Take a look around the site, that is pretty common. Use P0171 site:gmtnation.com to search google, it will search this site.