Regular maintenance of your Volvo EGR valve is not a common requirement; however, to ensure that the exhaust system of your Volvo is at its best condition while complying with the emission standards, the EGR valve must not be ignored for a long time. Once the exhaust system of your Volvo uses a defective EGR valve, expect that the engine will be seriously put at risk. The usual symptoms of a damaged EGR valve are the engine knock, poor gas mileage, reduced performance, and excessive emissions. The EGR valve is the main component in the EGR system. Its small vessel opens between the manifold and exhaust for the backflow of a metered amount of exhaust. The combustion temperature is reduced through that backflow while the formation of nitrogen oxides is regulated. Exhaust is driven back to the combustion chamber since the exhausted air is hotter that the intake air. The NOx emissions are produced from burnt fuel at 2,500 degrees Fahrenheit. In 1973, the EGR valves were introduced because of the serious damages brought by emissions. The Older vehicles used to have the mechanical engine EGR valves while most of the vehicles today are having electronic valves that employ one or more solenoids or small stepper motor. Once the engine is cold and idle, the EGR valve is kept closed. It only opens once the engine has warmed up and is running in part-throttle. The disconnection of the valve will cause the increase of the NOX emissions, resulting to detonation. If the valve fails to close, it will work as a vacuum leak that will result to a rough idle, hesitation, and possible stalling. Our 24-hour online store has a comprehensive catalog of parts that will provide you an organized list of our quality EGR valves in stock. Such catalog is designed to facilitate your easy Volvo EGR valve search.