2.3 litre engine. Both the EGR and PCV are next on my list. I have had EGR issues with other cars, but they always acted as a rough loping idle, not a long extremely high idle, then an almost so low it stalls idle, then a high idle (but not quite as high), etc., until it warms up and then seems fine.

But I appreciate the thought. If I get no-where, the EGR does seem like the next likely culprit. Maybe the IAC is working right and trying to compensate for a sticking EGR. sooner or later I'll figure it out.

Did I mention that this is a rather poor time of year to be working outside?....LOL.