my buddy eg has a f22 throttle body. the problem he has is the car revs up and down. so what do you guys think it is? tps, iat, a vac line?

 

Remove the breather and plug the bottom hole in the intake with your finger, if the engine doesn't stall then it's a vac leak. Though with it revving up and down I don't think a vac leak is the culprit. I'd have him clean the IACV with brake cleaner and try that.

Also, is it cold where you live? Is he letting the car get to normal operating temperature?