Air intakes help the engine to function because fuel cannot burn on itself. Be it petrol or diesel, oxygen is vital for combustion. The function of air intake is to ensure a continuous supply of fresh oxygen to the engine. Car intakes have an air filter to filter out dust and other impurities in the air. On top of that, a typical air intake has a mass flow sensor to measure how much air is flowing through it and a valve to control the airflow. That’s how air intakes ensure an adequate flow of oxygen for efficient combustion. Also, the airflow should not be too much as well. The airflow sensor and valve work together to achieve this.