i have a gsr swap and when i start it up it idles at like 500 rpms and then when it gets hot and i drive on the expressway it revs up to almost 2000 rpm and stays like that, when i hit the throttle it revs up then revs down to 1000 rpm and then back to 2000. i dont get it, im running a p28 chipped ecu, im running i/h/e/im, i was running rich a couple of weeks ago but i reset my ecu and now its acting up, please help, im guessing i need a tune which i am planning on doing