Exhaust Gas Recirculation: Description and Operation

CONSTRUCTION

The system consists of an intake manifold mounted EGR valve and connecting hoses. The vacuum to the EGR is controlled by the Electric EGR Transducer (EET). The EET is a dual (electric/vacuum) function switch. It is controlled by the engine controller.


PURPOSE

The EGR system reduces oxides of nitrogen (NOx) in the engine exhaust. It also helps prevent spark knock. This is accomplished by allowing a predetermined amount of hot exhaust gas to recirculate and dilute incoming fuel/air mixture. This dilution reduces peak flame temperature during combustion.