All Models (Ported EGR Valve)
Disconnect vacuum hose from EGR valve. Warm engine to normal operating temperature. Connect a hand-held vacuum pump to EGR valve. With engine idling, apply 8 in. Hg to EGR valve. If vacuum holds and idle becomes unstable or engine stalls, EGR valve is functioning properly. Reconnect vacuum hose. Increase engine speed to 3000-3500 RPM. Ensure EGR valve opens.