Subaru Repair: idling problem in subaru wrx, subaru wrx sti, sti version

Question
hey i have subaru wrx sti version 4 and i am having alot of troubles with the idling in goes right down to 0 and just about stalls then bounces back up to a 1000rpm then does that a couple of times goes back to the normal rpm point, but sometimes it stalls. would this be the o2 sensor?

Answer
Hey Sam

It could be one of many things.  Installing any part without a diagnoses performed by someone who knows Subaru is a gamble.  Is the WRX STI  stock or modified? If it is modified start with checking the MODS.  If not it may be the "N"(neutral) switch is worn and not sending the proper signal to the ECM (Engine Control Module)  but it could also be many other things as well.