I was almost thinking the same thing, that the IACV is somehow malfunctioning in a subtle way.

Usually the junk yards around here are cleaned out of every usable part for 6th generation accords. I'm gonna keep checking though.

I just had a new ebay IACV but it was aftermarket and brand new, it had intermittent issues with idle surge (my stock old one didn't) so I returned it. It was hard to tell if it really made a difference really because of its own issues.

I cant see spending the $$ on an OEM honda one without knowing it will solve the problem.

Will report back when I find an OEM IACV

I appreciate the help.

 

Update:

I found a used IACV in a junk yard. I cleaned it out really well and installed it. The IACV seems to respond quicker idle does seem to come down slightly faster now especially when cold. If I floor it in 1st, it doesn't hang nearly as bad when changing to 2nd,;however when the car warms up the idle seems to hang a little bit compared to when driving cold.

Upon unplugging it with the car running, the idle still bounces around a little so the base idle cannot be set. Again I can find no vacuum leaks I've been meaning to dig out my vacuum gauge to double check the idle vacuum, but I haven't found it yet.

The vacuum hose on I know of on the intake are:
Brake Booster (top)
IACV assist (on iacv running to lower intake)
Evap purge( on upper)
Cruise control (top of TB)
FPR (top of TB)
Transmission (top of TB - capped off b/c of manual transmission)

Am I missing any?

That said, the upper intake gasket and egr valve gaskets are only a few months old.