See Figures 1
The Exhaust Gas Recirculation (EGR) system recycles part of the exhaust gases into the combustion chamber to lower the peak temperatures. By lowering peak temperatures, a reduction in Oxides of Nitrogen (NOx) is obtained. The system consists of an EGR valve, thermo valve and a catalytic converter. California models use an EGR Control Solenoid Valve and an EGR Temperature Sensor.