I've got a problem with my idle dropping very quickly and then jumping right back up to where it should be. It does not do this while driving. Only while idling. This problem started this week.

changed-
plugs, 2,000 miles NGK irridium
plug wires, 10,000 miles should still be fine NGK 8.5mm
pcv, 2,000 miles
MAF, 2,000 miles
oil, 2,500

checked-
vacuum leaks, none found
ran b12 chem-tool in fuel
ran seafoam through intake
ran seafoam in oil (flush for oil change tonight)

I have only 2 days left to solve it before NOPI. I want my engine running smoothly for the 250 mile drive to the big car show.

bumpzors! What have I missed? I just got an oil change at lunch. Still same problem.

I was recently running rich because of o2 sensor problems. Other then cleaning spark plugs, what else should I do?

 

your o2 sensor could be causing the problem. It wouldn't hurt to change it out.
Did you run seafoam through the IAC?

 

Could be kinked Idle hose, while your there check the connection to the idle actuator.

O2 sensor could cause the problem as well.

now does it do this sometimes, often, or during every idle?

Also, a good reset of your ECU is in order