Exhaust Gas Recirculation (EGR) is a nitrogen oxide (NOx) emissions reduction technique used in petrol and diesel engines. The main function of the EGR valve is to reduce emissions by rerouting some of the exhaust gases which have been produced by the engine back into the combustion chambers in the engine, reducing temperatures within the combustion chamber.
EGR works by recirculating a portion of an engine's exhaust gas back to the engine cylinders, sometimes via the turbocharger compressor section.
In a petrol engine, this inert exhaust displaces the amount of combustible matter in the cylinder. In a diesel engine, the exhaust gas replaces some of the excess oxygen in the pre-combustion mixture.
Because NOx forms primarily when a mixture of nitrogen and oxygen is subjected to high temperature, the lower combustion chamber temperatures caused by EGR reduces the amount of NOx the combustion generates.
Most modern engines now require exhaust gas recirculation to meet emissions standards up to and including EURO 6 levels.
Symptoms of an EGR valve problem include; Rough engine idle speeds, Increased fuel consumption, Overheating, Pinking and knocking, and increased emissions, which can lead to NCT/ DOE test failures.
Assured Performance now stock a complete range of OEM EGR valves and Electronic Control Valves related to the EGR system for all vehicle makes and models. Please contact us for further details and pricing.