Description And Operation: Operation: Notes

The EGR system recirculates exhaust gases back into the intake manifold to be mixed with the incoming fuel/air mixture. This helps reduces combustion chamber temperatures improving emissions and fuel economy. The hot exhaust gases are cooled by the EGR cooler before reaching the EGR valve. The EGR temperature sensor is positioned between the EGR cooler and EGR valve. The feedback signal from the sensor is used to monitor the cooling efficiency of the recirculated exhaust gases passing through the EGR cooler assembly. The EGR system does not operate at idle. It typically operates during steady state speeds. A stuck or leaking EGR valve can cause engine stumble, sags, hesitation, rough idle, engine stalling and driveability concerns.