EGR Valve: Description and Operation

PURPOSE
The Exhaust Gas Recirculation (EGR) Valve is a vacuum operated valve which opens and closes a passage from the exhaust manifold to the intake manifold. This allows flame temperature in the combustion chamber to be lowered by diluting the incoming mixture with exhaust gases limiting the formation of Oxides of Nitrogen (NOx).


OPERATION
At specific times determined by the Engine Control Module the EGR Valve opens and allows exhaust gas to flow to the intake manifold.