The function of the automobile air filter element is to filter the dust and debris particles in the air and ensure that sufficient clean and dry air enters the cylinder.

The methods for judging whether the air filter element is dirty are as follows:

1. It can be seen from the operating state of the engine that if the air filter element is dirty, the intake air will be insufficient, and the fuel combustion will be insufficient, which will lead to the unstable operation of the engine. When the accelerator pedal is continuously pressed, the engine sounds dull, the acceleration reaction is slow, the operation is weak, and the exhaust gas is rich and black.

2. The color of the surface of the air filter element can be checked. If the filter paper is still gray black after the dust on the surface of the air filter element is cleaned, it indicates that the filter paper can no longer be used and should be replaced immediately.