Where is the air quality sensor of Volkswagen Touran?

The air sensor is located on the intake hose between the air cleaner and the throttle.

The air sensor, also known as the air flowmeter, is used to detect the air intake of the engine, and convert the air intake information into an electrical signal through circuit connection and input it to the ECU, so that the ECU can determine the fuel injection quantity and ignition time. The intake signal obtained by the air flow sensor is the main basis for ECU to control fuel injection. If it is damaged or its circuit connection fails, the air intake measurement of the engine will be inaccurate, and the mixture entering the cylinder will be too rich or too thin, which will lead to the ECU's inability to accurately control the fuel injection, resulting in abnormal engine operation and excessive emissions.