Quote Originally Posted by SlowNA06 View Post
How many miles are on this car? Could be a gummy throttle body, dirty maf, massive random vacuum leak...
What he said.

Sort of sounds like what you go through when tuning a cammed car for idle.
So that means, possibly vacuum leaks (intake manifold gaskets, tb gaskets vacuum lines fell off), dirty throttle body, air filter, intake hoses.

and SES light?