What part of the engine is responsible for controlling the fuel-air mixture in an Audi 80?

I'm having some issues with the fuel-air mixture in my Audi 80. I suspect it may be due to a faulty part in the engine, but I am not sure which one. Can someone help me identify the specific component responsible for controlling the fuel-air mixture in this car model?

The part you are looking for is called the fuel pressure regulator. It is responsible for regulating the amount of fuel that is mixed with the air in the engine. If this part is malfunctioning, it can cause issues with the fuel-air mixture ratio.

Another possible culprit could be the mass airflow sensor. This sensor measures the amount of air coming into the engine and sends that information to the engine control unit, which then adjusts the fuel-air mixture accordingly. If this sensor is dirty or faulty, it can cause problems with the fuel-air mixture.