TwoMuchMud , did you find a solution to your problem?
Sorry, I lost my account details for the other account but I never did fix this.
It has gotten a lot worse the last few weeks. Very rough low idle that shakes the whole truck. A new symptom is sometimes a very high idle/running speed of 3k RPM or so. Vacuum lines still seem fine, IAC or TPS are the only other things I can think of that could cause this. The TPS tests fine so that leaves the IAC.
I'm fairly convinced it's the IAC but I have never figured out how to get to that stupid thing. It seems 100% impossible without removing the whole intake manifold.