99 vette has a rough idle when warm?
Recently my winter car (subaru) threw a code. It was the idle air control valve. So I unscrewed it (very close to throttle body) and it had a lot of black gunk around it - it draws air/crap from the crank case. And I cleaned it all out.
I haven't checked it on my LS1 yet but it might help if you did.



