Yes sorry I do have a autronic ecu and the afm is gone.

Nails what would you recommend as a good cleaning agent to use to clean the parts with?

Thank you all for your help.

it needs a retune me thinks

Carbie/Throttle body cleaning spray available at most auto places repco autopro supacheap and the like.
The one I have used in the past is a xylene based product in a reddy color can, this stuff will remove sh*t form a blanket good stuff.
It evapourates very quickly so spary it on and briskly clean.

Had problems in my GC8 a while ago with idling and it seemed to do the trick.

Good luck.

Nails

My 04 idles at 500rpm when warm, only had it since early jan this year. It doesn't really worry me but should it?

oi dude its your Acceleration controller...i had same problem you have to reset it...go to MMS steve will explain how to fix it ...All up it takes 30 seconds to fix of a matter of taking a cord out and putting it back in...

its idling too low. get it checked. the engine would probably be shaking a bit with such a low idle = bad for your engine mounts

Thanks mate, it doesn't seem to shake at all (that i can notice inside the car), but yes i best ask a mechanic about it.

EXACT SAME PROBLEM.

99 WRX.

Autronic SMC, been a while since a tune so i suspected this...

But, she runs very nicely, just idles 1300 - 1500 when warm. It's pissing me off