First of all i am throwing no CEL's. just recently, i changed my IACV because my idle was fluctuating and i was throwing a CEL... i put a new one on and it idled like a champ up until about a week ago. recently when i'm pulling up to stop i either push in the clutch or just put it in nuetral and the RPM's fall to idle ( about 800) then raise immediatly to like 11-1,200, then settle back to 800 slowly( w/in a few seconds). i have no idea what is causing this and if someone could help me out i'd be great. oh yeah it's a 00 Si. thanks

 

ne1 have an idea??

 

i think you got a vacume leak....re-check everything...

 

maybe a bad o2 sensor...(upstream, on the exhaust manifold)...exact thing happened to me on my Si