How to Tell If an EGR Valve Is Clogged: Symptoms, Diagnosis, and Fix
A clogged EGR valve causes a rough idle, particularly at low RPM and at fully warm operating temperature, because carbon buildup either holds the valve partially open (allowing unmetered exhaust gas to dilute the air-fuel mixture at idle) or holds it stuck closed (causing elevated combustion temperatures, increased knock, and ECU timing retard that destabilizes […]