Exhaust Gas Recirculation: Testing and Inspection

Chart C-7:

INCORRECT EGR OPERATION:

1. If too much EGR is flowing at idle, cruise, or cold operation,
any of the following conditions could exists:
a. The engine dies after cold start.
b. The engine stalls on deceleration.
c. The vehicle surges during cruise mode.
d. Rough idle.

2. If the EGR valve is open during various engine conditions, the engine may not idle.

3. If too little or no exhaust gases flow, the combustion chamber temperature may increase under acceleration or heavy load conditions. These conditions could cause:
a. Detonation (Spark Knock).
b. The engine to overheat.
c. The emissions test to fail.