95 gst rev problems

[black2gst]

Its a 95 gst stock with stock boost.

Whenever the car idles revs will bounce to 2k then back down repeatedly. Although sometimes it wont do it at all or the revs may stay at 2k and slowly go back down to idle. Some people say IACV. any other input? btw whats the best way to clean out the IACV?

[asshanson]

Do you have the water lines hooked up to the throttle body? If not thats probably it. Or you may have a bad idle controller (IAC/ISC), change it out with a known good one to see if it helps.

[Kevin 1G Drummer]

Also check for boost/vaccuum leaks.

[black2gst]

well it threw a code and it said "The PCM has determined that a malfunction exists in the idle control system."