An EGR valve helps to improve the performance and economy of a vehicle while reducing emissions by directing exhaust gases back into the cylinders of the vehicle for a second burn. The valve reduces nitrous oxide emissions and directs the warmer exhaust back into the engine, reducing the amount of work required by the fuel-and-air mix in maintaining the engine at operating temperature.Continue Reading
The first EGR valves were simple orifices that directed exhaust gas back into the engine. They resulted in several problems, including difficulty starting, poor fuel economy, rough idle and poor performance. Manufacturers redesigned the EGR valve to use the manifold vacuum to keep the valve closed when starting the engine and open it once the engine reached a certain temperature. Although most engines continue to use the EGR valve to meet 2014 emission standards, some manufacturers are finding options that eliminate the valve while still meeting the requirements.
A dirty EGR valve in an engine affects its performance. Many are easy to clean by soaking in carburetor-cleaning fluid. A vehicle owner who attempts this fix should ensure he does not expose electrical connections to the cleaner. Once the device is cleaned and reinstalled, there is usually a noticeable difference in the performance of the engine.Learn more about Car Parts & Maintenance
Diesel exhaust fluid is a non-hazardous solution applied to the exhaust stream of diesel vehicles to break down nitrous oxide emissions into nitrogen and water. This system, called “selective catalytic reduction,” is found on 2010 and later model diesel vehicles.Full Answer >
Diesel exhaust fluid is an engine fluid used in selective catalytic reduction systems to help cut down on the nitrous oxide emissions of diesel engines. The heat generated by the DEF allows the selective catalytic reduction system to break down the nitrous oxide into innocuous elements.Full Answer >
Catalytic converters are emissions devices in vehicles that convert the harmful components in the engine's exhaust gas into harmless ones. This significantly reduces the amount of pollutants that a vehicle releases into the atmosphere. Catalytic converters are muffler-shaped and lie within the exhaust, and they contain catalysts, such as palladium and platinum, arranged in a honeycomb shape that react with the harmful components in the exhaust stream.Full Answer >
Secondary air injection systems are used for emissions purposes, where extra air is injected into the exhaust stream of an engine to burn the leftover fuel in the exhaust stream. This is because there's always some fuel that isn't burnt during the combustion stroke. So, to meet emissions regulations, the smog pump injects air into the exhaust, where the heat and pressure burns the fuel.Full Answer >