Exhaust gas cooling reduces temperature peaks during combustion and reduces the combustion velocity. This results in up to 70 percent less nitrogen oxides. Many EGR coolers feature an electrical or pneumatic bypass flap. When the bypass flap is closed, the exhaust gases are fed past the EGR cooler during the warm-up phase. This enables the engine and the catalytic converter to be brought up to operating temperature quickly. The 3D animation shows the design and features of the compact Pierburg aluminium EGR cooler module with integrated EGR valve and bypass flap.