Need some advice, or someone who's had this problem. I have a 88 corsica with the 2.0L. The car surges when idleing, more so in drive but alittle in park. As soon as I push the gas it goes away it seems. It gets more noticable when the car is warmed up. Feels like the car wants to die, but luckily it doesn't. So far I'll taken the throttle body off, cleaned it, cleaned the IAC. I have also replaced spark plugs, fuel filter, and fixed a small vacume leak. I think it's either the IAC or the TPS but I'm not sure how to test them.

Any DTC?

nope none

Check for vacuum leaks.

Take some carb cleaner and spray along the intake manifold if it smooths out you probably have an intake leak. You can pull the idle air control valve and clean it. A leaking egr will cause problems. Spray also along any gasketed surfaces.