The valve's performance is notably improved, reducing emissions and promoting cleaner air, all while maintaining the efficiency. 57mm 2.25inch EGR Valves Assembly For 1.9 130 160 BHP Automotive Replacement Exhaust Gas Recirculation. Effectively reduces nitrogen oxide (NOx) emissions in engine exhaust. The inner wall of the flow channel is smoothly polished to reduce the adhesion and accumulation of particulate matter in the exhaust gas. EGR valve controls the amount of exhaust gas recirculated to the intake system and reduces the emission of nitrogen oxides in the exhaust gas., Manufacturer: mangchengsm