All modern diesel and gasoline engines are equipped with exhaust gas recirculation (EGR) systems to help reduce nitrogen oxide (NOx) emissions from the engine. An EGR system works by routing a measured amount of exhaust gas back into the engine intake system. As the exhaust gas mixes with the fresh air-fuel intake charge, it lowers the combustion temperatures inside the engine cylinde... https://timessquarereporter.com/business/exhaust-gas-recirculation--egr--system--reducing-emissions-by-recycling-exhaust-gases