silly high idle when engine is cold

Hey there,

My 99 5 speed was doing great for the past year and then I road tripped it to Johnson city TN about 3 hours from me and when I got off the interstate the idle was about 2k. It ran great and throttle response was normal. Had my day and went back home and for that 3 hour drive it did great, other than I couldn't let off the throttle to slow down, almost always had to use brakes. When I got into town, I stopped for some food in a drive though and the coolant temp went over 210, but not by much. The next day she still idles really high but once she warmed up the idle drops to about 1k. That's been pretty consistent for the last week or so.

I have unplugged the IAC, engine dies
Checked for vacuum leaks, none that I can find and when I pull and vacuum line off the engine dies
Haven't checked or messed with the TPS because throttle response has always been good
Haven't messed with MAF

Something changes from when the car is dead cold(70F) to when it starts to warm up(150F) that cause things to line up and the idle to drop.

Could it be EGR? How would I test EGR? Something else?

Thanks!