when i step on the gas theres a slight hesitation and then it revs. the idle is rouigh to the point were i can feel it in my seat. also every so often on the down revs the engine will fall below idle and then shoot back up, sometims stalling. then others the idle will stick high like 2k. i was thinking it was the IAC, or the tps (for the shitty responce). i checked the IAC and machanicly it looks fine. i put fuel injector cleaner in it and it feels a little beter but not great. any ideas?

 

What year is the car?

 

Since you have a IAC I am going to guess that you have a fuel injection engine. What you will want to check is your MAP sensor to see if it is working properly, and you will also want to check each injector to see if they are within OHM specs. If you have a injector or two out of spec. this will be a common issue with drivability. Also you will want to do a leak down check on your injectors, if you have a leaky injector or a bad o-ring, leak down will show this, you are flooding your engine in one or more cylinders. Over all if you are getting a error code check to see what the code is and start there first, most likely going to be a O2 sensor or faulty IAC, even if you inspected it and it looks good does not mean it is working, this I know from experience.