Rick's Free Auto Repair Advice

Clean a MAF sensor — step by step guide for DIYers

How to Clean a MAF Sensor And Get Quicker Starts

Carmakers say you can’t clean a MAF sensor you must replace it. They’re wrong. You can clean it, but it’s very delicate and must be done with care. I’ll show you the step-by-step process to clean yours. But first, let’s go over the basics:

What does a MAF sensor do and how does it do it?

A MAF sensor calculates the volume and mass of the air entering the engine so the ECM can calculate the right amount of fuel to add.

The MAF contains an air temperature sensor and a hot wire or hot plate. The wire or plate is heated to a predetermined temperature. As flowing across the wire/plate causes it to cool. The MAF sensor tracks how much power it takes to keep the wire/plate at a set temperature. Based on the amount of power needed to maintain the wire/plate temperature, along with the temperature of the incoming air, it can calculate the air’s volume and mass in grams per second.

Why the MAF may need cleaning

Over time, the wire/plate can accumulate a coating of fibers from the air filter and oil from crankcase vapors. Anything that lands on the hot wire or plate can bake onto the surface, insulating it and causing it to send inaccurate data to the ECM.

How to clean a MAF sensor without damaging it

The hot wire is thin, delicate, and easily damaged.

You can spray it with aerosol MAF sensor cleaner but never use a rag, cotton swabs, metal objects, or even your fingers. If you damage the wire, you’re buying a new sensor, and they’re not cheap.

NEVER use compressed air to clean the sensor

Where is the MAF sensor located?

The MAF sensor is located between the air filter and the throttle body.

image showing location of Mass airflow sensor
Disconnect the sensor from the air duct

The sensor is often held in place with large clamps. In this image, you see one end clamped to the air intake duct and the other end bolted to the air filter box. Remove the clamp and nuts and remove the sensor.

Image showing where to disconnect sensorThen disconnect the sensor’s electrical connector

Press down on the tab on the connector and wiggle it out of the sensor.

showing how to disconnect sensor connector

Locate the sensor element

image showing MAF sensor element Locate the small circular opening inside the sensor.

Aim the straw at the sensor element and soak it with the cleaner.

Allow the element to completely air dry for at least 30 minutes before reinstalling. Lingering cleaner residue can damage it when electrical power is reconnected.

Don’t allow the straw to touch the element and don’t use any object like a rag or Q-tip to touch the element. It’s very delicate and can break easily.

Reinstall the thoroughly dried sensor back into the air intake tube, and reconnect the wiring harness clip. Make sure the sensor orientation matches the factory direction.

CRC MaF sensor cleanerClear any Mass airflow-related trouble codes before starting the engine. Test drive to ensure cleaner has fully restored sensor function.

Be very gentle and use only approved electronics/MAF cleaners to keep from damaging sensitive components. Take care not to bend or break the delicate wire sensor element inside.

Find CRC MAF Sensor Cleaner at any auto parts store or online at amazon

NOTE: Ricksfreeautorepairadvice.com receives a commission on products purchased through amazon links.

© 2012 Rick Muscoplat


Posted on by Rick Muscoplat

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