EGR System - Gasoline: Description
The Exhaust Gas Recirculation (EGR) system recirculates exhaust gases into the combustion chamber to reduce combustion temperatures. The reduction in temperature acts to reduce oxides of nitrogen (NOx) emissions. The system consists of an EGR control valve (2 on Calif. Stanza), thermal vacuum valve, and various connecting hoses and tubes.
In addition, a venturi vacuum transducer (VVT) valve is used on Pickup, Pulsar, Sentra, and Stanza. A vacuum delay valve is used on Pulsar (High Altitude), Stanza (Calif. Non. M.P.G.), and Sentra. A vacuum switching valve and vacuum switch is used on high altitude compensation (HAC) equipped Sentra. A vacuum reservoir tank is used on Calif. Stanza, and high altitude compensation (HAC) equipped Sentra. Minor differences exist between application of thermal vacuum valves on all models.