EGR Control Valves
- Warm engine to normal operating temperature. Stop engine. Detach EGR vacuum sensing tube from EGR valve and apply intake manifold vacuum directly to EGR valve.
- Pinch off intake manifold vacuum hose while engine is restarted. Release hose. If EGR valve is okay, engine will idle very rough or stall. If idle quality does not change, replace EGR valve.