hi, when i picked up me scoob from the docks it wouldnt idle too well i.e. revs hunting between 300-1200, often stalling if i didnt rev it, seemed worse when warm. then a week or two later it seemed to magicly go away!

however it's come back after a few months with the same symptoms! it's pi$$ing me off. dont know if it would make a difference but i dont use the car all that often and it seemed to come back this time after a fairly high speed 180 mile drive (m-way).

any suggestions very much appreciated. ta.

 

From what I have seen on here in the past sounds like your maf

 

Typically caused by either the MAF or the Lambda sensor. The MAFs are now considered as replaceable items on the MY99/00 motors and if it hasn't been replaced it would be a wise service precaution to reaplace it regardless. Faulty MAFs have been known to destroy engines, particulalry on an import.

When I collected my MY99 STi RA I found after a blast down the motorway, or a good thrashing anywhere would result in the revs leaping from about 500 rpm to 1200 rpm, this was casued by a knacked Lambda sensor (Service life of about 30,000 miles).

MAF's can be got direct from Subaru dealers for about 70 quid (don't let them try to sell you the whole houseing for about £240), Lambda sensors can be got from them for about the same or from 3rd party suppliers such as Cats direct for the princely some of £35. Many people would probably tell you to avoid these, but at £35 it's difficult to go wrong and I've been using mine for 6 months and all is still well.

 

brilliant info thanks guys ...

 

I think "donut man" () has summed it up pretty much, but here's a couple of things I picked up on...

MAF, lambda sensor, or ICSV.

Absolutely certain it's your MAF sensor. Your ECU had managed to learn it's way around the fault. If you had performed an ECU reset, you would probably have found your idle (and driving) was pants again.

Had you made any changes to the car? Reset the ECU at all? What sort of air intake is on the car (standard air box or aftermarket induction kit)? What brand of filter? Something seemed to make the fault worsen beyond the ECU's capability of correcting it, but not bad enough to display a CEL...

 

LOL, I saw that and thought "Guy's gone crazy, don't remember seeing no Donut Man post on this thread ..... then the penny dropped

Fixed it BTW (well, kinda), does seems it's the wheel bearing that's allowing enough movement for part of the disc to rub on the backing plate behind it. I've actually taken a file to the disc for now (it's not the disc itself, just a bit that sticks out from it). I may change the wheel bearing at some point, but all seems well for now ....

 

Good man.