Does '96 have a FITV? I know they eliminated it by '98, but which years??

If it does have one, check whether the plunger inside has become loose. Screw it back in & make sure there's no air pockets. Check for air pockets in the cooling system anyway, because they'll confuse the IACV also.

Set your base idle, maybe it's up too high?

Check for vacuum leaks.