Rough, Unstable Or Incorrect Idle & Stalling: Sensor/System
WARNING: This page is about a different car, the 2003 Cadillac Seville and 2003 Cadillac DeVille. However, it is still accessible from the selected car via links, so may be relevant.
- Test the Positive Crankcase Ventilation Valve (PCV) system for proper operation.
- Test the throttle body, and Throttle Position (TP) sensor for proper operation and damage.
- Inspect the Knock Sensor (KS) for excessive spark retard.
- Test the Exhaust Gas Recirculation (EGR) system for proper operation. See EXHAUST GAS RECIRCULATION under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING - 4.6L DEVILLE & SEVILLE article.
- Inspect the Idle Air Control (IAC) valve and valve housing for deposits and/or damage.
- Inspect for dirty or damaged air cleaner element.
- Inspect for collapsed or damaged intake air ducting.