Exhaust Gas Recirculation: Description and Operation

Operation

The function of the Exhaust Gas Recirculation (EGR) system is to reduce emissions by recirculating exhaust gases back into the inlet manifold thus reducing peak combustion temperatures and NOx Emissions.
The system comprises an EGR valve and transfer pipe. The EGR valve is fitted to the rear of the induction elbow below the throttle body. The transfer pipe connects the right-hand exhaust manifold to the EGR valve.
The EGR valve is driven by an integral four pole (60 step) stepper motor controlled from the ECM.
The valve is cooled by the coolant return from the electronic throttle body.
When the EGR system is not fitted, a blanking plate is bolted onto the induction elbow.