2001 pontiac idle problem

An idle that high is almost always a vaccum leak. Did you replace the O-rings on the injectors?

No, I did not try that. I replaced the intake manifold gasket, and found a small leak on the oil pump, so replaced that gasket, but nothing else. No new codes come up on the computer. I have heard it could also be clogged fuel injectors, vaccuum leaks, or a AC sensor. Have you seen this?

Make sure the injectors are properly seated. You should be getting a code with an idle that high (when in closed loop).
The best way to diagnose this problem is to use a scanner and verify all sensors are in range.
If it idled properly before the repairs, then idled high afterwards, it is most likely the repairs caused it.