So I took it in, and the IAC was apparently not functioning at all, so it was replaced. More expensive than it could have been if I had done it, but faster than I could have gotten it done with my work schedule; it's my daily driver, and I would have hated to have to cancel my dinner date with my kid tomorrow night. The VX purrs now, fingers crossed that it lasts.

Thanks for all the advice, if I continue to have problems, I will start with the MAF and such.