2001 W/ high idle
 

Hello all,
The Sonata idles at 1800rpm in park/neutral. The idle doesn't change from cold start to full operating temp. When in gear the idle is pulled down to 900rpm and when the A/C compressor cycles the rpm will increase about 50rpm, so I think the idle control servo is working but I'm not sure. There is NO check engine light. The engine occasionally runs rough and lacks power. I removed and inspected the intake hose looking for leaks and found none.
I need your help!
Thanks

It's probably the ICS valve if there's no intake leaks. You can test it by removing the thing and plugging up the holes. Did you do a code scan anyway? Don't drive like that too much, as it will burn up your transmission.

Yes, tested for codes and found none. Today I drove it a little then parked for awhile, when I re-started it idled at 800RPM but as I drove it home the idle returned to 1800RPM.
I guess if I remove the IACS and plug the hole it would narrow it down a little, Throttle Position Sensor, IACS, or something else telling the IACS to open the throttle.:confused:

It won't idle high unless it gets air. It's either getting air from the IAC or an intake leak.