Secondary Air Injection Archives - UnderhoodService
EGR, Secondary Air Injection And Emissions Management

EGR systems put a small amount of inert gas into the combustion chamber to control the temperatures.

Secondary Air Injection Tips

Secondary air injection can be supplied actively from an electric air pump or passively from pulse pressure in the exhaust system. In a passive/pulse system, air is drawn in when a valve opens from vacuum created through exhaust flow. In an active system, air is blown from an electric pump, which allows for better control.

EGR And Secondary Air Injection And Emissions Management

The perfect internal combustion vehicle would be able to put the exact amount of fuel and air into the combustion chamber. If the perfect combustion event were to occur, you would get nothing more than water and carbon dioxide as byproduct. There would not be any unburned fuel or oxygen. Combustion would occur at the right temperature so oxides would not combine with nitrogen and carbon to form nitric oxides (NOx) and carbon monoxide (CO). This perfect car would not need a catalytic converter or any other emission-control device.