EGR System: Description: Notes

The Exhaust Gas Recirculation (EGR) system is designed to lower burning temperatures of gases in combustion chambers, thereby reducing formation of oxides of nitrogen (NOx). Metered amounts of exhaust gas dilutes air/fuel mixture, lowering combustion temperatures.

System consists of a diaphragm-actuated EGR valve, Coolant Temperature Override (CTO) switch and connecting hoses. 1975 Calif, and all 1976 engines use an external Backpressure Sensor (BPS). 1977-79 models use an EGR valve with integral BPS.