My Rs turbo S2 idles at 950 rpm as it should and pulls alright (maybe a slight hesitation when accelerating at low rpm, but not completley sure) but it is pretty rough at idle, and when i drive op to a red light signal or some other kind of stop, my idle drops Down at 500-600 rpm and then comes back up to 950 rpm again after 5 seconds or so, and as i mentioned, it then idles rough.

Could it be my auxiliary air valve? Or have you got any other suggestions? :/

Cheers