00 jdm b18cr w/mugen chipped ecu, stock internals---- idles fine when cold-1200....when warm at stop it will fluctuate from 800-200 rpms or so and almost sound like its gonna bog out but wont.....doesnt always happen but most of the time will..... any ideas what it is?

 

If your engine has a fast idle control valve on it (hanging below the throttlebody).

There are several other possibilities, all of which could be found by searching.

 

huh...thanx for the help

 

do a search under FITV

 

or IACV (Intake Idle Air Control Valve)

 

thanx fellas...ill clean the IAVC and see if that helps