Yes, another one. Sort of. Well, I believe my IAC is sticking, it usually gives me a high idle and I've gone and checked for vacuum leaks finding nothing. It is a part store brand that is out of warranty, so I am thinking it is going to buy the farm here soon. Looking online there is a difference between IACs depending on the year of the car for all PI 4.6's. I'm running a Trickflow plenum/TB and bought the one that resembled closest to the OEM one when I replaced the OEM one. Is there any difference between the ones that have the black cap and ones that don't?