Let me put ti nice and simply, I'm no mechanic, but I happen to have pretty much the same problem, (my truck constantly looses its idle, it soars up to 12RPM and runs really rough) from reading all comments up to yours I do have a question, when you recommended to clean the tubing inside the plenum where carbon deposits should be normal, after all we're talking about a 20 plus years vehicle would you also recommend checking the EGR for the same purpose as well as the AACV, mine was replaced four years ago and the EGR was also replaced more recently, the old one was practically blocked with soot and dirt, truly hope you"re still around your comments are right to the point and the make a lot of sense....