Thanks Tony, I had the fuel filter replaced at 60k miles, the IAC at 65 (though didn't seem to make any difference to idle - I found a leaking PCV rubber tube at the exit that was the problem), and the UIM and LIM have both just been cleaned up with brand new gaskets. Idle is SOOO much better (most of the time) than it was before I had that done I can't imagine a leak there. When the idle problem happens, it is very very bad and often will die, when it isn't there it is smooth as silk (close to when this thing was brand new!). I also have both the Ford moose fix pipe and the drilled plug in my car - the combination has worked well for a few years. Could the IAC act weird only 10% of the time? What else could be wrong?
