2007chevy5.3l

iTrader: (21)

Okay so I either have a big *** vac leak/exhaust leak or a crappy o2 cause my truck all of a sudden started freaking out and running like **** at idle/part throttle, along with LTFT logs pegging out a 25% and a CEL saying bank 1 lean conditions.. Ive been running the same original tune for 1.5yrs along with the headers/cai. This issue seems to be getting worse so im thinking its a O2 sensor which are original with 52k miles...
So has anyone else seem to have a similar issue??

02'Z71ONDUBZ'

iTrader: (8)

Are your trims on both banks acting a fool or just bank 1? You should be able to hear an exhaust leak but I don't think that would cause this issue anyways. A vacuum leak could definitely cause it to run similar, but I think it would have to a pretty bad one which should be fairly easy to diagnose. I would lean towards the o2's...

2007chevy5.3l

iTrader: (21)

Im going to test the o2 voltage and see if I can find something.. The bank 1 is way off. Bank 2 isnt off as much.

BlackGMC

iTrader: (31)

Swap the o2 sensors side to side and see if the problem follows. That will prove if the sensor failed

2007chevy5.3l

iTrader: (21)

I will try that trick also. Sure hope its just a bad O2

DanszToy

Curious if you found the trouble, I got a similar issue with both LTFT's .

2007chevy5.3l

iTrader: (21)

Have you tried cleaning the MAF with MAF cleaner? When I did that to mine the trims quit maxing out and were in more reasonable +/- percentages. I still have issues but they are in other areas....