An Exhaust Gas Recirculation (EGR) valve is a mechanical component found on automobiles and plays an integral part in the proper functioning of gasoline and diesel-engined cars. It ensures that the car burns its fuel effectively by recirculating the emissions from the exhaust through the car’s combustion system. Properly recirculated fuel results in cooler and fuller burning, along with a reduction in the quantity of harmful gases, especially nitrogen oxide (NO). When NO meets the air, is turned into nitrogen dioxide, which in turn becomes smog when it encounters hydrocarbons. In vehicles where the EGR valve is faulty, the driver commonly finds that acceleration is difficult or that the car experiences rough idling or stalls.
The first EGR valve was installed in cars in 1972. They were originally mechanical, and have been superseded by the more modern and much more sophisticated electronic valves. The latest versions are not only capable of self monitoring, but they periodically create problems for the system to ensure the correct response is produced.