EGR System: Description

The Exhaust Gas Recirculation (EGR) allows a predetermined amount of exhaust gas to recirculate to the intake manifold, diluting the incoming air/fuel mixture. This diluting of the air/fuel mixture reduces peak combustion temperatures. The lower combustion temperature reduces emissions of oxides of nitrogen (NOx). California models use on-board diagnostics for the EGR system. The diagnostic system uses a solenoid in the vacuum line to the EGR valve.