Exhaust Gas RECIRCULATION (EGR): Notes
To lower oxides of nitrogen (NOx) exhaust gas emissions, an EGR system is used. The EGR system introduces exhaust gases into intake system. The exhaust gases are noncombustible gases which, when combined with incoming air/fuel mixture, lower peak combustion chamber temperatures.
EGR valve receives ported operating vacuum through a control regulated EGR Vacuum Switching Valve (VSV). ECM regulates VSV based upon input signals from various sensors. Control vacuum is further regulated by an EGR modulator, located in vacuum line between EGR valve and EGR solenoid.