Air Flow Meters, Air Mass Sensors (MAF’s):
What Is An Air Flow Meter?
The air flow meter is an electronic device which measures the amount of air flowing into the engine. It sends an electronic signal to the ECU which then calculates how much fuel to supply so that the correct air/fuel ratio is maintained
What Happens When They Go Wrong?
A faulty or out of spec air flow meter can cause all kinds of problems such as
Poor performance and poor fuel consumption
An engine that won't rev over 2 or 3 thousand rpm
Flat spots, hesitation, juddering, exhaust smoke, stalling or an engine that won’t start at all
So if you have any of these issues then the air flow meter could be the culprit…...and i say could because it’s not always easy to pinpoint a faulty MAF even with the cars on-board diagnostic diagnostic software.
How Do They Work?
Hot wire air flow meters like this one have an electrical element inside them which heats up when you start the car. Over time the repeated heating and cooling gradually degrades the element and it can also get dirty, tiny particles of dirt that get past the air filter stick to the hot element and eventually the air flow meter will start to send incorrect readings to the ECU
The big problem is that airflow meters can go out of spec which means they continue to work but outside of their specified operating window...so they continue to send a signal to the ECU but it's a weaker or incorrect signal. If this happens, your car will probably be running like a bag of spanners but unless unless the MAF breaks altogether the ECU may not have registered a fault.
So if you send your car into the garage or plug in a diagnostic reader you could have a faulty air flow meter but may not get any fault codes. That’s why changing the air flow meter is often the 1st thing that people suggest if you've got these poor running characteristics but no fault codes
How To Replace An Airflow Meter:
Replacing an air flow meter is a pretty simple job. In most cases they are easy to locate and work on and they can usually be changed with just a few basic hand tools in a relatively short time. The tools You’ll need will vary from car to car but in many cases a socket set, screw drivers and pliers are all you will need.
Check out our ‘How To’ video for a full demonstration:
