Just curious about fuel trims.
If they are showing negative, what's going on and what does the engine need more or less of?
Same question for positive high numbers.
Where would these changes be made?
Of course, I'm talking here that it's been verified no exhaust or intake leaks.
I was running my 5.3 with what I discovered to be a PCM from a 4.8 liter. I changed all settings to 5.3 stock and it's running worse. A bit of stalling and negative SFT's.
Sorry, at work now, don't have a log file.
Just curious about basics and where to begin to correct/tune.