My son has a 2011 XC90, six cylinder. He has been getting the P0171 code. We read the freeze frame for the fuel trims and there are two sets. STFT/LTFT #1 and STFT/LTFT #2. #1 was reading out of range like 40' and 30's. #2 was reading what I think was good. Like -3 each one. Have replaced cats, MAF sensor and O2 sensors. Also did a smoke test and had no leaks. Any ideas???

 

That's an expensive list of parts to throw at this DTC. The trim you should care about is Long Term. The Short term will go all over the place. Check the long term trims, determine rich or lean, and go from there.

 

Thanks, also any idea which bank is which. Is bank #1 cylinder1,2,3.?