99MY - when warm seems to hunt up and down a bit at idle - not a lot (+/- 100rpm) but never did it before.

Any ideas please ?

MAF sensor - get checked asap :eek: If busted the engine may underfuel causing it to go bang!!

The above is the worst case scenerio, could be something simple.

My 98 wrx does too, also for some reason it makes the whole car shake too when idle!!

lamda sensor (in down pipe) is another possibility

Saxo Boy

Already had a 'went bang' engine (fortunately under warranty) but will get dealer to check MAF and lambda, thanks.
Doesn't do it all the time though

Flat 4x4,

I've got the same problem with MY99 and had the sensor in the MAF and the o2 sensor replaced and still vibrates on idle. Taking in again for a full days worth of investigation

Have you found out what it was yet??

Andy

In the dealer tomorrow - remind me if I forget to report back

Could be throttle position sensor if MAF and O2 all ok

Was told yesterday by dealer that they are going to contact Subaru Technicalbefore they do anymore tests on the car. I mentioned the throttle response sensor but he did'nt sound that interested.

Only error logged was O2 sensor related, so replaced under warranty. Still doing it though. Unless it gets worse I'll leave until the next service .

Try cleaning inside of throttle body/idle control valve. Use carb cleaner. If it's ever been overfilled with oil, both can get crap in them which means idle control has to work too hard, or is sticky.

Andrew

What does it look like ?!
I had a go at the boost solenoid once so its not that !

simple one but make sure all hose clips are tight, harder than it sounds, there is bloody loads of em :D

My car hunts a little at idle like yours. I logged the RPM on my new home made select monitor :) , and it seems to only be a fluctuation of 25 RPM! It feels like it's varying very much more than that.

I wonder how much better I can get the idle? I have just about cleaned everything... I'm tempted to stop worrying about it :rolleyes: