EGR Valve: Testing and Inspection

1. Run engine until it reaches normal operating temperature, then shut off engine.
2. Disconnect and plug vacuum hose of EGR valve.
3. Disconnect vacuum line between thermo sensor and inlet manifold at inlet manifold.
4. Using suitable vacuum hose, connect inlet manifold directly to EGR valve.
5. Pinch hose between inlet manifold and EGR valve, then start engine and ensure it idles smoothly.
6. Release pinch and ensure engine idles rough.
7. Connect all hoses to proper locations.
8. If test results are unsatisfactory, clean or replace EGR valve as necessary.