rough idel, hunting

[jsidik]

i've got a similar problem on my 02 wrx, but with a high idle. i've tried cleanin the maf sensor, cleaning the idle air control valve, adjusting the throttle and cruise control cable, and anythin else people here have suggested. none have helped me, but you could try those 3 things for starters.

 

[Nigel Prodrive]

model year 2000 IAC is often a problem with subies, the one on the transplanted 00 RS motor in my rally car drove me nutz. never did really sort the issue, even after replacing a whole bunch of stuff. seems that some IACs have the problem, others don't

sorry not to have silver bullet fix, first check IAC to make sure the plates in it don't have any hang-ups that can cause erratic idling, if they catch or act weird in any way, replace IAC with new part, cause used ones almost always act weird when transplanted to new used motor. (don't axe how I learnt this)

 

[jsidik]

I just checked the codes on mine and got a P0102 (MAF Circuit Low Input) but it didn't come up until about a month after the problem started. Try cleaning the MAF Sensor on the top of your airbox and the electrical connector if you havn't already. Otherwise check out this link. He's got a really good write up on IAC valve cleaning. The Gasoline Method Worked really well for me, but unfortunately for me this wasn't the problem. http://forums.nasioc.com/forums/showthread.php?t=781242