California

EGR System (California):

Exhaust gas recirculation, is used to reduce oxides of nitrogen emissions in the vehicle exhaust. EGR uses partial recirculation of the exhaust gases from a port in the cylinder head to a port in the intake manifold. The EGR valve controls the flow of exhaust gas in response to 'E' port vacuum. At partial throttle settings 'E' port vacuum is high and the EGR valve is open. At full throttle and idle 'E' port vacuum is low and the EGR valve remains closed. The ECU, thru the EGR control solenoid valve, prevents EGR operation until the engine reaches operating temperature. The ECU uses the temperature sensor to determine when operating temperature has been reached.