Car revs up and won't rev down. Changed ICV
High idle problems are often times related to vacuum leaks or lean fuel conditions. I would start by checking for vacuum leaks and other fuel delivery components, such as the mass air flow sensor (https://www.yourmechanic.com/services/mass-airflow-sensor-replacement), injectors (https://www.yourmechanic.com/services/fuel-injector-replacement), throttle body (https://www.yourmechanic.com/services/throttle-body-replacement),...