if your not sure if the throttle plate is getting stuck open, either A...take off the intake and look, or B remove the throttle cable temporarily. its also a common charactericitc of a vacuum leak. spray brake parts cleaner all over the manifold and vacuum lines while the car is on. the car will bog down bad if its able to suck it in through an open vacuum. also make sure the tps is reading the correct voltage. it could also be a bad iacv or something with the fuel/timing and maybe even the ECU could be messed up. too many variables. check everything one thing at a time and eliminate the ones that u check. or do it the easy way and take it to someone who knows what theyre doing and save the time and frustration. either way, good luck.