The wire receives a certain amount of electrical current and as the air moves over it, it cools the wire and changes the electrical resistance. There are different reasons why you can use a blow through setup but we will not discuss this here.

This is referred to as a “blow through” MAF setup. Some turbocharged aftermarket setups locate the sensor in the piping after the turbocharger (pressurized piping). This is also referred to as a “draw through” or “pull through” MAF sensor. In most OEM intake systems, it’s located a very short distance after the air filter. The MAF sensor is a wire located directly in the middle of the airstream somewhere in the intake pipe. Once it measures how much air is coming in, it then sends that information back to the ECU so that the fuel injection system knows exactly how much fuel your engine needs to match that amount of air and perform whatever function it’s supposed to be performing at any given time in the rpm and load range. The MAF sensor is used in the intake system and it is designed to measure the amount of air flowing into an engine. Although a MAF based vehicle typically uses a MAP sensor in addition, they are separate sensors altogether. A MAF (mass air flow) sensor is not to be confused with a MAP (manifold absolute pressure) sensor. Let’s start with understanding how a MAF sensor works. But increasing the size of the intake diameter isn't the only thing you have to worry about in a MAF based car and it doesn’t have anything to do with actual power production. Sure, a bigger intake typically yields more power through less restriction and more airflow. Over the years, we’ve found that many people who are modifying their MAF controlled car have a misunderstanding of what needs to change or be modified in order to make more power when it comes to the intake system.

Mazda 3 mass air flow sensor problems