A. Most 1973 and later model vehicles are equipped with an exhaust gas recirculation system to recirculate proper amounts of exhaust gases into the air/fuel mixture in the intake manifold. This recirculation into the manifold reduces combustion temperatures, thus reducing oxides of nitrogen (NOx). There are several types of EGR systems: a back pressure system which operates in conjunction with exhaust back pressure, a conventional system which operates on carburetor venturi vacuum, an electronically controlled system which operates from the engine computerized emissions control system, or a floor jet system which operates through jets in the floor of the intake manifold.
|Procedures:||Reject Vehicle If:|
|(1) Inspect for presence of exhaust gas recirculation system.||(1) Exhaust gas recirculation system is required and any part is missing.|
|(2) Inspect for condition of exhaust gas recirculation system.||(2) Hoses, pipes, tubing, valves, or jets are damaged, disconnected, plugged, cracked, leaking, or improperly connected.|