Exhaust Gas RECIRCULATION System: 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, Sentra, Stanza, 210 and 310. A vacuum delay valve is used on Calif. Stanza, Non. M.P.G. Sentra, 210 and 310. A vacuum switching valve and vacuum switch is used on high altitude compensation (HAC) equipped Sentra, 210 and 310. A vacuum reservoir tank is used on Calif. Stanza, and high altitude compensation (HAC) equipped Sentra, 210 and 310. Minor differences exist between application of thermal vacuum valves on all models.