Exhaust Gas Recirculation: Description and Operation

The Exhaust Gas Recirculation (EGR) system recirculates portions of the exhaust gas back into the engine to reduce the amount of nitrogen released during combustion, and to reduce combustion temperature. The amount of exhaust gases released into the engine is proportional to the load on the engine.

One of two possible EGR valves will be used. Which EGR valve the engine is equipped with depends on whether the vehicle has:

EGR Valve:

MTX (M/T) with Federal or Canada emissions

EGR Valve:

CD4E (A/T) or a California vehicle with an MTX

If the vehicle has the CD4E (50-state and Canada) or is a California vehicle with an MTX, the EGR system uses both an EGR vacuum regulator solenoid and a EGR vent solenoid. Both solenoids are located on a bracket under the intake manifold.