[rovingryan]

On my 07 I have been struggling with the P0171/174 bank1/2 lean faults for almost a year now. It started out after a long highway drive which is probably unrelated. I ran some fuel injection cleaner on two consecutive tanks thinking maybe I got some bad fuel. That made no difference so I have smoke tested the intake and found only a leak at the orings on the PCV. I replaced and retested to verify that leak was resolved. However the problem persists. Long term fuel trims indicate an intake system leak. I have disconnected the egr pipe and verified no smoke past the seat when the egr is closed as well. I have verified and reflashed the pcm with the latest firmware to verify it is not a mapping issue. I will try to post screenshots here showing the data but over 2500 rpm the fuel trims are near 0%. At idle they are 14% bank1 and 12% bank2 and gradually drop as rpms increase. If I manually select gears and intentionally load the engine at low engine speeds to get the throttle plate open the trims drop to 4% or so. Looking for any further advice before I take it in as it is coming up to tab renewal which requires a DEQ test. MAF tests ok as well and swapped it with a friends lr3 and the readings stay the same.

 

[gravitylover]

Interesting. Did you ever go deeper with this and figure out what was wrong? I run an UltraGauge so I get live readings and the differences between banks 1 and 2 on both long and short term trims are huge sometimes. Granted, the sampling rate is too slow though. I have the very occasional rough cold starts with misfire codes and random 0171 and 0174 codes but no evident leaks.

 

[rovingryan]

I ended up replacing the air filter, cleared the codes and reset adaptations one last time and it has not returned.