Exhaust Gas Recirculation: Description and Operation

EGR Valve:

PURPOSE
The Exhaust Gas Recirculation (EGR) system is used to lower Oxides of Nitrogen (NOx) emission levels caused by high combustion temperature. It does this by reducing combustion temperatures.

The main element of the system is the linear EGR valve. The EGR valve feeds small amounts of exhaust gas back into the combustion chamber. With fuel/air mixture thus diluted, combustion temperatures are reduced.