Exhaust Gas Recirculation System (EGR System) (Opel Omega B)

The diesel fuel system is equipped with an exhaust gas recirculation (EGR) system to reduce the content of nitrogen oxides (Nox) in the exhaust gases. Part of the exhaust gases are returned back to the engine to reduce the combustion temperature and thereby reduce harmful impurities in the exhaust gases.

The system is regulated by the DDE control unit at an increased amount of injected fuel, according to the signal from the accelerator pedal sensor, the speed sensor, the atmospheric pressure sensor and the coolant temperature sensor. The control unit, by means of a vacuum control valve controlled by the EGR valve, correctly doses the exhaust gas. The EGR valve is located on the intake manifold. At a low coolant temperature or if the engine load is high, the exhaust gases do not return. The exhaust gas recirculation system does not require frequent maintenance.

(Source is on this resource opelbook.ru)