dookiepoo22

I got a 97 impreza outback sport and After driving on the freeway for more than 15 minutes the idle is up at like 1500 to 2000 rpm. It wont respond to me slakening the idle adjustment. Usualy in a couple day days to go back to normal hella randomly. The only thing thats for sure is it happans after freeway driving. Im tryin to save money to get my wrx back on the road so any help before i have to take this thing back to garage one is much appreciated