Exhaust Gas Recirculation: Description and Operation

CONSTRUCTION

The system consists of an EGR tube connecting a passage in the intake manifold (below EGR valve) to the exhaust manifold. It is also equipped with an EGR valve, vacuum transducer, EGR vacuum purge solenoid, and connecting hoses.


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.