How the Secondary Air Injection System Works



A secondary air injection is an automobile emission control system that operates by injecting the fresh air into the exhaust stream to allow the fuller combustion of the exhaust gases. The primary methods of implementation of the secondary air injection are the pumped air injection and the aspirated air injection. The system is used in vehicles that use petrol since it helps in decreasing harmful substance emissions during cold starting. For an effective cold starting, a petrol engine requires that the fuel and the air mixture contains additional fuel for proper combustion. more  website


The secondary air injection is an essential method of lowering the high levels of carbon monoxide during cold starting.  It, therefore, makes an important impact on reducing the harmful substance emission and guaranteeing obedience with the existing emission standards. Besides, the secondary air valve is installed in the secondary air pump. The pipes come in different designs. The secondary air stops the exhaust gas and pressures peaks in the exhaust tract thereby destroying the secondary air pump. The secondary air shut-off valve, on the other hand, ensures that the secondary air is only supplied to the exhaust gas manifold during the cold start phase.  more here  secondary air injection
When the engine of a car is running, there are some portions of unburned fuels that do not get a converter to power the engine during combustion. The unburnt gases also referred to as hydrocarbons, are then released with other exhaust gases. The hydrocarbons are an essential component of the fuels that provide power. However, they can be poisonous, thereby calling the need to burn them as much as possible. Burned fuel is less toxic to the environment than unburned fuel; therefore it is crucial to ensure that almost all fuels are burned to avoid emissions of the unburnt gases that can end up polluting the environment.  
The secondary air injection system, assist in cleaning the unburnt fuels. For the fuel to be burnt, it needs to be pressurized; first, the injector pushes the air into the exhaust compartment to burn the unburned fuels. Governments have set the emission standards; therefore the system assists in achieving the standards. The air injection helps in improving fuels efficiency as well as generating more boost for the vehicle. However, it is not a must for every car to be installed with the system. Other measures that can assist in improving the car boost include removing some electrical components of the vehicle such as air conditioning. more  https://en.wikipedia.org/wiki/Secondary_air_injection