Exhaust Gas Recirculation: Description and Operation

PURPOSE
The Exhaust Gas Recirculation (EGR) system is used to dilute the incoming air/fuel mixture with recirculated exhaust gases. Dilution of the incoming mixture lowers the peak flame temperature in the combustion chamber and thus, limits the formation of Oxides of Nitrogen (NOx).

OPERATION
This system uses an electronically operated EGR Valve. At specific times as determined by the Engine Control Module the EGR Valve opens and allows a controlled amount of exhaust gas to be introduced to the intake system.