stuck on OL /CL, rapid looping between the two ∞

[BG1988]

some times it will revving very high as well when idle



the idle oscillation as well between 589 to 660rpm the throttle position changes as well from 19.8% to 21.5%(oscillation without touching it) you can see the engine run lean to rich per this "oscillation"..


it also opens the EVAP_VP purge valve in a "rapid fashion" which is also oscillation between a negative and positive value


sometimes the engine upon a cold start will stumble on it self


occasionally there will be a SUPER IDLE surge from between 1200rpm to 2000 or more RPM..

The above does not happen if I remote start the engine 9 times out of 10


where are the vacuum lines at? 6.0 LS based engine (some are obvious like the two near the oil filler tube ) i checked the hoses between the air filter and throttle body they are secure..

i'll pick up a few incenses(as i don't smoke) to look for vacuum leaks

there has been no loss of MPG currently getting 22.9MPG in the city...

 

[BG1988]

can't diagnostic as it was behaving today 99% of the time

it did backfire upon a cold start below 8C (reports of an ECM update for this.."fuel mixture issue ")

some point to a vacuum leak or timing issue oh ECM going bad?

some report this that 2008 needs a PCM calibration update? or is the VVT damage? it has had the emissions recall update. all the links for these TSB are gone, censored or buried away to hide the information.. i did pretty good today like i said it was behaving 31.3MPG latest highway 176 mile run (new personal best)

so it's not like it's dumping fuel into the tail pipe..