Engine revs up and down at idle with code p1514 and p0420.

P1514 is related to the idle air control valve which is what is most likely causing the idle issues. That would be the first thing I check. As far as the P0420, that is related to the catalytic converter working below expectations. Fix the IAC first and see if that eliminates the P0420 problem. Let me know if that takes care of it.

The IAC is located on the throttle body. It requires the removal of two screws and disconnection of wires to it. Then it is just a matter of removing and replacing.

i changed the iac valve....i tried to reset the codes but they come right back...today a new code of p1443 showed up....the car started this morning and cut right off....i pumped the gas a few times and it started....when i started driving and put it in neutral the car reved all the way to 4000rpms for a few seconds and then started surging from 1000rpm to 2000rpms...i noticed in second gear at full throttle it had a little sputter or hesitation to it for a breif second...
but it continues to rev up and down from 1000rpms to 2000rpms at idle or in neutral even after i replaced the idle air control valve

Have you checked if the IAC is getting power?

no i havnt...should i do that with a test light or something else?

i tested it and it has power going to it

Okay, it is getting power. Do this now. Remove the IAC and have a helper turn the key from off to the run position (engine off) and see if there is movement in the pintel.

i did that...the iacv prong does move in and out

Have you checked for vacuum leaks?

yes..no vacuum leaks