1977-79 Models

Starting at a coolant temperature of 62°F (17°C) on 1978 230 models or 104°F (40°C) on all other models, a portion of the exhaust gases from the exhaust manifold is recirculated into the intake manifold during acceleration, part throttle operation and deceleration. The amount of EGR is dependent on the position of the throttle valve and the exhaust gas backpressure in the exhaust manifold.