EGR System: Description: Notes

The Exhaust Gas Recirculation (EGR) system is designed to lower burning temperatures of gases in the combustion chambers due to lower concentrations of oxygen in the intake mixture, and thereby reducing formations of oxides of nitrogen (NOx).

This reduction of combustion temperatures is accomplished by introducing metered amounts of exhaust gas into the air/fuel mixture, lowering combustion temperatures. The EGR system used on the 1.4L and 1.7L engines is controlled by the Electronic Control Unit (ECU). This system consists of a diaphragm actuated EGR valve, EGR valve solenoid, connecting vacuum hoses and ECU.

The EGR system used on the 4.2L engine consists of a diaphragm actuated EGR valve, Coolant Temperature Override (CTO) valve, a Thermal Vacuum Switch (TVS) and connecting vacuum hoses.