so over past week my check engine light has come on , a P1131 code has shown up saying bank 1 O2 transitions are running lean. And on my way home from work today my battery gauge continued to drop until I got home and parked and at the moment my truck completely died. So am I looking at multiple issues such as a leak somewhere in the line and a alternator issue? Or could the battery dying all be a result of the truck running lean for a week? Any advice would be greatly appreciated!
Thanks,

 

i want to say probably try the same things I am that the others have posted & suggested. I hope we both get it figured out soon! Good luck! Let me know if there's anything I can do to help! I know I will watch your progress & figure things out as we go!

 

Around the back of the engine, center of the intake manifold is a large rubber elbow. Check this elbow for damage, it is well known for causing lean codes.

 

@rodney_langton


I am a little surprised the shop didn't do a little more diagnostics to narrow things down for you.


You need a look at 'LIVE' Short Term Fuel trims and O2 sensor activity - similar to the attached Torque Pro scanner screen.


First problem with the printout the shop handed you is - DTC's are 'sticky'. A condition (like that reported) causes the DTC, then if the condition disappears - the code remains, at least for some number of drive cycles before the PCM will clear it. Some will not even clear when the condition rights itself and must be cleared with a code reader (such as Torque Pro). But ONLY 'live' data will indicate if the condition causing the DTC is still present - and it may NOT be or you would likely have other codes - such as Cat Efficiency code, or you would have a 'Flashing' CEL if there were that many misfires.


Second, Freeze frame data should be considered. It can be enormously helpful to know other things going on at the instant the DTC was 'set', such as vehicle speed, engine RPM, Engine Load, Accelerator position, Coolant temp, Intake air temp, Total runtime this drive cycle, to name a few.


Third, If its a vacuum leak - Short Term Fuel trim would be very POSITIVE in an effort to compensate for a vacuum leak. (In MOST cases, the PCM can compensate for a vacuum leak by increasing injector pulse width --- BUT will lead to a P0171 before the O2 sensor stops switching completely - resulting in a P1131).


If the Fuel/Air ratio (Mass Air Flo versus Fuel Trim) is within tolerance, your failure of the O2 to switch constantly like it should (See attached Torque Pro graph on top) could be either the result of 'TIRED' O2 sensor, 'WEAK' heater element, OR perhaps a defective fuel injector delivering much more fuel than it should for a given injector pulse width.


CONCUSION: You need more data, or you're working in the dark.


Good Luck.






O2 Sensors (Bank 1 & 2), Short & Long Term Fuel trims (Bank 1 & 2).