EGR System: Description
The Exhaust Gas Recirculation (EGR) system reintroduces exhaust gas into the combustion cycle resulting in lower combustion temperatures and reduced nitrous oxide (NOx) emissions.
The amount of exhaust gas and the timing of the cycle varies according to calibration as determined by engine speed, engine vacuum, exhaust system back pressure, coolant temperature and throttle opening. All EGR valves are vacuum actuated. See emission decal for vacuum diagram and calibration.