What does an air injection pump do?

The air injection pump, an integral component in the emission control systems of many vehicles, serves a crucial role in reducing harmful pollutants released into the atmosphere. Positioned within the vehicle's exhaust system, this device operates by introducing clean, compressed air into the exhaust stream before it exits the vehicle.

Primarily, the air injection pump aids in the afterburning or secondary combustion of unburned fuel and exhaust gases remaining in the engine. As the engine runs, there might be incomplete combustion, leading to the generation of harmful pollutants within the exhaust. The air injection pump addresses this by supplying fresh air into the exhaust manifold or catalytic converter, where it reacts with the remaining fuel, burning it more completely.

By introducing additional oxygen into the exhaust system, the air injection pump facilitates a process known as secondary air injection. This process effectively promotes the oxidation of pollutants like hydrocarbons and carbon monoxide into less harmful substances like carbon dioxide and water vapor. As a result, this mechanism significantly contributes to meeting stringent emission standards imposed by regulatory authorities worldwide.

The functionality of the air injection pump is particularly crucial during a vehicle's cold start. During this phase, engines operate less efficiently, and the catalytic converter might not yet have reached an optimal temperature for effective pollutant conversion. The pump aids in this period by accelerating the heating of the catalytic converter through the introduction of air, enabling it to reach its efficient operating temperature more rapidly.

While the design and application of air injection pumps may vary across different vehicle models and manufacturers, their fundamental purpose remains consistent: to minimize the environmental impact of automotive emissions by promoting the thorough combustion of exhaust gases before their release into the atmosphere.