Chrysler Repair: High Idle, air leaks, vacuum hose

Question
Hello--2001 Chrysler 300M, 91k miles, suddenly started idling at 3-4k rpm. No MIL, no DTCs on core reader; no obvious air leaks; IAC valve replaced--did not help. Appreciate any suggestions!

Answer
Hi Zoran,
Two things to check: the throat of the throttle body may be dirty so clean its throat, and both sides of the butterfly plate and the side passageway for idle air. The other is for a vacuum hose that is disconnected at the intake manifold or at the far end of the hose to whatever it is supposed to be attached. Use the underhood vacuum hose diagram as a roadmap to check all the possible disconnects. The feedback loop can cause a high idle rpm when there is a leak of air into the manifold that is otherwise not measured by the system.
Roland