My engine revs at high rpms when idle and higher than normal rps when in hear, making it slightly harder to come to a full stop. I believe it is either the tps or the iac. I would like to check before sending it to the dealership. Any ideas? Where is the IAC located?

SOURCE: car wont idel and revs some times for no apparent

If it has a carberator check to make sure that the throttle linkage is in a relaxed position when the car should be idoling in other words if the linkage is too tight then while your gas pedal may not be pressed the linkage is so tight that it is still pully on the throttle linkage and causing it to rev. The only reason i can think of it revving on its own though is maybe a tension spring on this linkage is broken and the linkage is loose and flopping back and forth from idel to throttle with bumps and other distrubances.

SOURCE: i have a 03 tiburon gt 2.7 and when you hit the

Check for air leaks between the Mass Air Flow sensor and the throttle body or a valcum leak.

SOURCE: did engine swap on 2000 sonata 2.5 v-6 and am

Fix the Throttle position sensor first, then see if things settle down, without that input, computer has to guess.

SOURCE: Do I have a possible IAC valve problem?

I would say that is EXACTLY what it is! you've already "tested" it.
you could try cleaning it out. carb and choke cleaner works good