Air Mass Meter?

Also known as a mass flow sensor, the Air Mass Meter is an automotive instrument that measures the mass of your engine's air intake. It's a simple plastic tube that has a set of sensors running through it. As the air passes through the tube, the sensor collects data from it, and then sends it to your engine control unit (ECU). While this sensor may be capable of measuring air mass, it doesn't measure the density of the air passing through its tube.

Now, you might ask why there's an Air Mass Meter in your car. Well, to put it simply, air is a vital ingredient in fuel combustion. Fuel needs to be mixed with air before fuel combustion can take place inside your engine cylinders. If the amount of air that mixes with your fuel is not in the appropriate air-fuel ratio, then your engine might run too rich or too lean—resulting in poor fuel efficiency. What this mass flow sensor does is it lets your ECU adjust your air-fuel ratio accordingly for optimal engine performance.

The only problem with an Air Mass Meter is how it's very prone to wire element contamination. This happens when dirt and debris that's being carried by the air gets stuck in the sensing wire element. When this happens, the unit's sensing wire has difficulties measuring air flow—thus preventing your ECU from receiving accurate data.