Ok after much searching and finding out just how many things may cause this issue I'm pretty much out of words. So my car has a lt1 from a 94 trans am "anniversary edition" but is a 01. What works has been done to it i have no clues other then cold air and headers and cat back. So I looked at one sight said to check header tube temps to find cold spots. well on left side of motor only 1 cylinder is hot. Is there a suggested first step to trouble shooting? It ran a lil ruff when i first bought it but after today its running like total crap. Im lost in the sauce on this.