car engine

How to Clean a Mass Air Flow Sensor: MAF Sensor Cleaner Beginners Guide

Does your car’s idle sound different? Is it stalling?

There’s a long list of costly repairs that it could need. Before you spend a bunch of money, there are a few simple things you can try and save big!

Your mass air flow sensor might be dirty, causing your engine to not get the right gas/air mixture. Cleaning this sensor is easy to do and is way cheaper than taking the car into the shop.

Read on to learn how to clean a mass air flow sensor in 4 easy steps!

What is a Mass Air Flow Sensor?

The Mass Air Flow sensor, or MAF sensor, is located in the engine’s air intake.

It measures the volume of air that the engine is taking in. The ECU uses this information to determine how much fuel to inject. A proper ratio of fuel mist to air is what makes combustions engines work.

Technically, the MAF sensor measures air density and not the actual rate of flow. Air density is affected by temperature, forced induction (turbo and superchargers), and altitude.

It is important that your MAF sensor is working properly to ensure the best fuel efficiency and engine function.

There are a few types of mass air flow sensors.

Hot wire sensors use a platinum wire which is heated by electricity of a specific voltage. Air passing over the wire cools it. The cooled wire is less resistant to voltage. The engine control module (ECM) measures the difference in resistance to measure air density.

Cold wire sensors function the same way, except that they also include a cold wire as a reference. GM engines use cold wire MAF sensors often.

When Should You Clean Your MAF Sensor?

A dirty MAF sensor can cause your car to “throw a code” and make your check engine light come on. Even if it hasn’t gotten to that point, cleaning your MAF sensor regularly can boost performance by 4-10 horsepower compared to a dirty sensor.

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Other indications that your MAF sensor may need cleaning include:

  • A hard-to-start engine
  • Stalling shortly after engine starts
  • Engine hiccups
  • Engine drags under load or while idling
  • Noticeable change in idle of engine

We recommend cleaning your sensor every time you change the air filter.

Once you know how to do it, it won’t take you long. Also, cans of MAF cleaner last a long time, so it’s a very cheap way to improve engine performance!

You should NOT use this method of cleaning if your vehicle has a Karman-Vortex style sensor.

Most Mitsubishi and Lexus engines have these types of sensors. They are also found on Toyota Supra Turbos. Maintenance on their Karman-Vortex sensors are best left up to Toyota dealers

Before You Begin

Before you begin, you’ll want to collect your materials. Here are a few of the items you will need:

  • MAF cleaner
  • A rag
  • Screwdriver or Torx tool (depending on your vehicle)

Once you have collected your materials, make sure your vehicle is parked on level ground with the emergency brake engaged. Make sure that you have the engine off before beginning. You should also allow time for the engine to cool before attempting to clean the MAF sensor.

Step 1. Unplug the MAF

Locate the MAF sensor.

It will be on the air intake tube or on the air intake side of the air filter. When you find it, it might be a good idea to snap a few pictures to remind yourself how to put it back. Taking pictures after each step of the removal process could save you a headache later!

Once you find the MAF sensor, unplug the wires running to it. If you can’t get your fingers into the plastic clip, use a standard head screwdriver to gently pry the release until it comes loose. It’s a good idea never to force anything. 

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Step 2. Remove the MAF from the Vehicle

Rather than removing the sensor itself from its housing, it will stay safer if you remove the housing as well. The wires inside the sensor are very delicate and damaging them will lead to a more costly repair!

The housing should be connected to the air intact by hose clamps.

Use a screwdriver to loosen the clamps so you can remove the sensor. Lay your rag flat on a bench or the driveway and place the MAF sensor on top of it so that you can see the sensor inside the housing. The rag will collect the excess cleaner from overspray.

Step 3. Spray Cleaner

Attach the straw to your spray can and begin to apply the MAF cleaner.

You should hit every part of the sensor with 10-15 bursts of cleaner. DO NOT let the straw touch the sensor. At no time should anything touch the actual sensor or you risk damaging it.

Be careful as you move the housing around, being sure to spray all parts of the sensor including the connectors and terminals.

Step 4. Reinstall

Let the sensor sit and dry for at least 20 minutes. Reinstalling while the sensor is still wet could damage it. You need to allow time for all the chemicals to evaporate before reinstalling and starting your car.

Once it has had time to dry, reinstall the same way you took it out, making sure to reattach the cables. It’s that easy!

Now You Know How To Clean A Mass Air Flow Sensor!

Knowing how to clean a mass air flow sensor can save you money and keep your engine running at its peak. You can avoid costly mechanic bills by doing this easy fix yourself!

For more great tips of maintenance and more, check out some of our other articles!