Just had my MY02 STi serviced (40000 mile service). No problems found including cause of knocking from suspension at low speeds (I expected this much). Started engine tonight - ran very roughly, idled at 500 revs then nearly stalled then horror, CEL came on. I switched it off and re-started. CEL still on but engine sounded ok-ish except a few pops from the PPP exhaust on revving engine, then all settled down to normal idle.

CEL remains on despite apparently running ok.
What could this be?

Clearly, returning to dealer is good idea but this'll be difficult for lots of reasons.

Any ideas?

D.

 

It has the signs of a maf sensor, best get to the dealer (gently) and get it checked....

 

Thanks RON

After an exhaustive search of MAF sensors, etc sounds like you're right.
Do you think the dealer has caused the failure during the service or has it just come to light with (I presume this was done) a ECU reset?

Is the MAF sensor a warranty item?

Thanks.

D.

 

If they changed the air filter there's a chance they damaged it, but doubtful, not sure if it's a warranty job, ought to be though!
Pretty sure they would not reset the ecu at service, just check codes!

 

CEL still on this morning and it started very roughly. Had to drive it this morning before going to dealer at lunch time. CEL went out mysteriously about an hour before I got there. Select monitor said that the Knock sensor had detected a fault (presumably a prolonged det episode) but everything was now ok. ECU was cleared and everything now seems ok.

The only explanation that I can think of is 2 tankfuls of Sainsbury SUL in a row. I normally exclusively fill up with Esso or Optimax but recent price risesin both of these had tempted me to drift to the dark side. I'll not make that mistake again.

D.

 

it probably was dodgey petrol.i was filling my wife's ka up in tesco's and got chatting to an s4 owner who was putting 95 ron in his car-said he was always taking it to the garage as it was running poorly and had hesitant acceleration-i would not touch supermarket petrol for a subaru
martin

 

for what its worth my MY02 cel light was due to the knock sensor. basically when i went full pelt 5.5-6k revs on the light came. had knock sensor replaced under warranty no problems since

also i had a 4yr old maf sensor changed under warranty on my MY99 which mysteriously went after a major service.

cheers

colin