High idle speed on 1994 Cadillac Seville

My mechanic can't seem to fix the idle speed. He's put in plugs and wires. He's set it to specs. I mean he has all the code readers and tools and knowledge.
Could this be the O2 sensor?

Asked by for the 1994 Cadillac Seville
1 answer
check all the sensors like the tps, iac and make sure it doesnt have a vaccuum leak