I have a 1993 Subaru Legacy 4WD SW (2.2L, 5-sp, non-turbo, w/AC), with 250,000 miles on it. In general, everything still works fine, but it idles too high at initial startup. If I let it idle for about 2 minutes, it drops from its 2k idle, down to about 700. If I just start up and drive, it tends to stay at 2k. Can you give me some hints?
Also, I had to helicoil my exhaust studs (all had begun to strip). One of them (inboard LH) is still stripping, so that side is not a good exhaust seal. Is that a possible reason for weird idle problems? If so, is there enough metal to go up a stud and helicoil size?

Thanks, in advance, for your help. I'm still on my first engine for this subaru (also a first!), and want to keep it going.

I have had the same problem with my 2005 WRX... The dealer mechanics told me it was the clutch, so we got that replaced for nearly $1500. Then it still happened, so they said it could be the power steering pump and neutral safety switch, so we got that replaced for $800. And it is STILL happening! I've been trying to find answers, but I can't. I did find this website though:

http://home.sprynet.com/~mklphoto/SUBARU1.HTM

That might help. It could be an alternator/voltage issue. I'm going to try to get THAT replaced now. Ugh this is a nightmare I just wanted to let you know you're not alone! Let me know if you find any answers, eh?