EGR System - Diesel: Description

Only California vehicles are equipped with exhaust gas recirculation (EGR). The system reduces oxides of nitrogen (NOx) by allowing a small quantity of exhaust gas to enter the intake manifold. This lowers combustion chamber temperatures and reduces NOx formation.

California vehicles use a vacuum and electronically controlled EGR system. The system consists of a electronic control unit (ECU), switchover valves, microswitches, coolant temp. switch, vacuum control flap, throttle valve housing, several orifices and a TDC transmitter.