Diagnose a Bad Mass Airflow Sensor & Replace It Yourself

Your mass airflow sensor (or MAF sensor) measures the amount of air that enters your vehicle's engine. This allows your car's engine control unit to know how much fuel is needed for proper combustion. But this sensor can fail. This guide will help you diagnose a bad MAF sensor and help you replace it.

Signs Of A Bad Mass Airflow Sensor

The following are a few signs that may warn you of a bad MAF sensor:

  • Rough idling
  • Hesitation when accelerating
  • A noticeable lack of power
  • You will have poor fuel economy
  • Stalling
  • Your check engine light might turn on

You can talk to your auto care specialist if you notice any of the aforementioned symptoms. Your auto care specialist can confirm your suspicions by performing a computer diagnostics.

Replacing Your Mass Airflow Sensor

You will need the following:

  • Your owner's manual
  • Gloves and safety glasses
  • Screwdriver
  • Socket wrench set
  • Clean rags
  • A new mass airflow sensor that is specific to your vehicle

Follow the steps below to change your mass airflow sensor:

  1. Park your vehicle on a level surface and in an area that is safe to work in. 
  2. Make sure your engine is cool. 
  3. Open your hood, and look for your mass airflow sensor. This is usually located between your air duct (or air boot) and your air filter body. You can also use your owner's manual to find the sensor. The sensor is usually sitting right on top of the air filter body and is sometimes labeled as the mass airflow sensor. 
  4. Disconnect your battery, just in case. 
  5. Remove your air duct from the air filter body using your socket wrench set. 
  6. Carefully dislodge the electrical plug from your mass airflow sensor. 
  7. Now you can begin to unscrew your old mass airflow sensor using your screwdriver or socket wrench set. 
  8. Carefully remove the old sensor, and replace it with your new mass air flow sensor. Use your rag to clean any area that has debris or dirt. This could be anywhere from the compartment that holds your mass airflow sensor to your air duct. 
  9. Screw your new sensor in, and reconnect the plug. Make sure the electrical plug has no obstructions that might interfere with your mass airflow readings. 
  10. Reconnect your air duct and battery. 

That is how simple it is to change your mass airflow sensor. Remember to talk to your auto care specialist (like those at Perfection Automotive Services) if the problem has not been resolved, as it may be related to your fuel system and needs further investigation.