I have a 07 Avalanche with a 5.3 in it that's driving me nuts, it's been months. Had multiple mechanics look at it. One day it just started running terribly and fat.
All stock except DOD was deleted in the computer. Shutters bad at idle and choppy under power.
Been through injectors, fuel pressure test, plugs, wires, sensors, compression test, exhaust gas dye test, even replaced the motor mounts. All is well. Zero Codes. Still runs poorly.
My obd2 reader shows a miss on cylinder 2 but HP tuners does not. The only evidence I have is this attached log.
Under power, MAF/TPS/LOAD/TIMING all start to oscillate. Timing is all over the place and it knock retards.
Someone please take a look at this log, it's from a cold start. 20 minutes worth of log with a WOT portion in it, lots of stops and starts. You will see what I am talking about.
Any help would be extremely appreciated.
2007 Avalanche 5.3 LC9.hpl