I had the same problem. Try this. Turn the key on and press the gas pedal to the floor hold it for 3 sec, let off, pump it to the floor 5 times in 7 sec let off Turn key off then start it . See if this fixes the high idle. If not follow Toms suggestions.
Is that some kind of idle re-learn?
98' GP coupe NIC Pacesetters, E85, FSIC, 2.6, heads, blah
11.82 @ 118.4 with a 1.8 60ft
Retired: 99' Regal GS Turbo 11.428 @ 122.61 1.7 60ft.
Retired: 99 GTP top swap nic setup. 13.37@106