EGR System: Description

Exhaust Gas Recirculation (EGR) is used on all Light Duty Emission models to reduce oxides of nitrogen (NOx) emissions. This process is accomplished by lowering combustion temperatures of burning gases. Recirculated and metered amounts of exhaust gases are reintroduced into engine through the intake manifold, where they are mixed with air/fuel mixture.

The vacuum modulated system regulates exhaust gas recirculation according to manifold vacuum. The back pressure modulated system regulates timed vacuum according to exhaust back pressure level. A special control valve within the EGR valve housing responds as a pressure regulator.