The air injection valve is a small but important part of the car's air intake system. Its job is to allow air from the air pump to enter the exhaust system whilst stopping the reverse flow of exhaust fumes back into the air intake system.
The air injection valve is usually found in the plastic housing between the engine and the air filter. It is attached to the air hose which is connected to the air flow sensor which is attached to the air filter box.
It is imperative that the engine is supplied with the correct amount of clean, filtered air. Air needs to be as clean as possible before it mixes with the fuel and burns in the cylinders of the engine. The air injection valve plays a part in this process by ensuring fumes do not go back into the engine. This type of valve is known as a check valve, because it checks or stops the flow of gas in one direction. It has an important part to play in the overall performance of the engine, enabling it to work as efficiently and effectively as possible. By stopping exhaust fumes from re-entering the car's air intake system, the air injection valve helps to prevent damage to the engine.
If there is a problem with the air injection valve you will see the Check Engine Light come on. You may also notice that your fuel consumption is significantly increased and your car's CO2 emissions may be higher. The air injection valve will wear over time and will eventually need replacing. Make sure that is the air intake valve that is faulty and not a blockage or problem elsewhere such as the air hose, air filter, air intake pipe or air pump. If certain the problem lies with the air injection valve, replacing it with a new air injection valve will mean you get the right part for the make and model of your vehicle.