Air is important not only to human beings, but to cars as well. You see, fuel isn't the only thing the engine needs in order to make the car move. The combustion mixture fed to the engine in order to produce power is a combination of air and fuel. The engine control unit (ECU) is responsible for determining the amount of fuel to be mixed with the air entering the throttle, keeping the mixture as balanced as possible. This helps your car's engine remain fuel-efficient and your car's exhaust emissions in check. To do its functions properly, the ECU depends largely on air volume readings sent by the mass air flow sensor.
This sensor is located between the air filter intake hose and the throttle. Most engines equipped with electronic fuel injection have coldwire-type sensors. Coldwire air flow sensors are basically oscillator circuits with a frequency that changes each time air passes through the wire. The volume of air passing over the wire is measured in relation to the change in oscillation frequency. The greater the change, the more air flow is present. The information from these mass air flow sensors is sent to the ECU, which then calculates how much fuel should be mixed with the air volume present in the throttle.
Since the ECU depends on the air flow sensor to determine the correct amount of air entering the engine, a mass air flow sensor failure can lead to combustion problems. Given the wrong inputs, the ECU could release too much or too little fuel into the engine. The imbalanced combustion mixture can cause your car's engine to hesitate or stall even during mild acceleration. You may even have problems starting the engine because it's either being flooded with too rich an air-fuel mixture or not enough fuel is being burned due to a lean mixture.
A quick way to test whether or not the car mass air flow sensor is working is to simply unplug it while your car's engine is running. If the engine stalls, then the sensor is fine. If it keeps running or it suddenly runs better, chances are the sensor is starting to give. Once this sensor fails, the ECU will switch into a failsafe mode, limiting the engine's maximum RPM (revolutions per minute).
If your car's mass air flow sensor is broken or worn out, replace it as soon as possible. When looking for a replacement, don't just buy any sensor. Make sure it's from a reliable brand sold by a reliable retailer like Parts Train. As a top source of quality OE replacement parts, our online catalog features air flow sensors only from top brands, giving you plenty of quality options. And with our low price guarantee, you'll get access to the best deals here.