P0171 code and stalles at stop

[HiHoeSilver]

A mechanic buddy of mine suggested it was the throttle body?

Not too likely with your symptoms. I would blame a dirty MAF before I messed with the throttle body, but either of those would translate on both banks. You are way more likely looking at a vacuum leak, a fuel delivery problem, or a bad o2 sensor.

 

[zell66]

i will try the O2 sensor and I am currently running a fuel cleaner through the system.

 

[HiHoeSilver]

i will try the O2 sensor and I am currently running a fuel cleaner through the system.

The fuel system cleaner is good either way. Beyond that, you need to see the scan data to make an educated move rather than just throw parts at it. Chances are that your sensor is fine and is just reporting on your real issue.

 

[gpracer1]

Try running the known good gas you have now until it gets low, if it does it again fill it all the way up (record number of gallons) and see if it is fixed again. It may be a fuel level problem, or reported fuel level like it says you have a 1/4 tank but its really emtpy-ish and you are running on fumes.
Could be fuel pickup issue.

 

[oldchev]

I agree.
If your problem exists when your fuel level shows under 1/4 then either your fuel is lower than you think or the fuel pick up is drawing air. If you have a fuel pressure tester (about $20 at HF) at the time symptoms are present, then attach the tester (if safe to do so) and check pressure. if its fluctuating you have one of the problems mentioned above.