Just got my 04 a week and a half ago. Perfect in every way except for the high idle problem. Joined up here and read every thing posted regarding this problem. Car came with a K&N CAI, flowmaster exhaust, 18" wheels, and I'm not sure about anything else. (tune, etc.) So here is what I tried:
New IAC valve.....no change
New TPS sensor.....no change
Clean everything (throttle body, pcv, mass airflow sensor, air filter) and check for vacuum leaks.....no change
Make that silly IAC restrictor out of metal from a discarded acetone can.....problem solved!
Go figure.........I just had to tell somebody.
Although the post is almost 8 years old, thank you mach1canuck