Well, it looks like I may *fingers crossed* have the subaru up and running. It was having a hard time with hesitating real bad and on a really hot day it just took a shit on me. Would start and run and held idle just fine, but no power. Would just hesitate under load. The last day I drove it it wouldn't hardly move. Had to leave it and go back that night and get it.
Always ran worse when it was hot outside.
Codes it gave me 2 were for the front air/fuel sensor and one was for the idle control valve. I replaces the sensor yesterday, and ran a can of sea foam through the intake and it helped but still not completely fixed. It ran ok and made a 30 ish min round trip but it was also just the low 80's here. Could still feel some hesitation though, and still hesitated hard at high rpm under half or more throttle. I bought new plugs, wires, changed the oil, new air and fuel filter. And it seemed to remedy most of it.
The power is back for the most part and in the high rpm range could still feel a slight hesitation but nowhere near as bad as before.
I cleared the CEL just to see (some people with similar issues reported an improvement for a short while after clearing the codes) so now I wait to see of it comes back on.
I'd say it is probably at about 95% fixed. I just don't know where else to look. I'd say maybe rear o2 but I have no issues at idle or low rpm really and no code for that.
People reporting online that the neutral safety switch on the manual subarus could cause some of the issues, if it's reporting that it is in neutral instead of in gear the ecu will think the icv is bad bc the rpm is too high.