System Testing, Calif.

1. Make a thorough visual check of system, wiping away oil as necessary to facilitate inspection. Replace any cracked or broken hoses and ensure all electrical connectors are securely connected.
2. With engine off, check EGR control valve for any indication of binding or sticking by moving diaphragm of control valve upward with finger.
3. Start engine and check EGR system operation. Place a finger on EGR control valve diaphragm and ensure valve moves to actuate system when coolant temperature exceeds 122°F.