Hi all, been having idle problems for two years and finally found a fix the other day!
I had tried all the usual things like spark plugs, cleaning iac, cleaning maf, checking for vacuum leaks and everything you could imagine. But when changing my spark plugs again last week i noticed the coilpack springs had arcing marks on them.. so while driving it around for the week after changing plugs (still with the idle problem) i decided i would clean the bottom of the springs with some 400 grit and put some dielectric grease on the bottom of the spring and top of the spark plugs. PROBLEM SOLVED! My idle is now steady and i no longer get that rich smell from my exhaust..
For anyone that is wondering, the spring is just inside the rubber coil pack boot - it just pulls straight off.