Mass Air Flow (MAF) Sensor: Symptoms and Cleaning Tips

The mass air flow sensor tells your engine how much air is coming in. If it gets dirty, the engine computer gets the wrong information, and the car can run poorly.

What the MAF sensor does

The MAF sensor sits between the air filter and the throttle body. It measures the amount of air entering the engine, and the computer uses that measurement to decide how much fuel to inject.

Symptoms of a dirty or faulty MAF

• Hesitation or jerking when accelerating

• Rough idle or stalling

• Poor fuel economy

• Black smoke from the exhaust

• Check engine light with codes like P0100 to P0104, P0171 or P0172

Why MAF sensors get dirty

• Dirty or poorly fitted air filters let dust through

• Oiled aftermarket air filters can leave oil on the sensor

• Engine oil vapour from the crankcase ventilation system

Jamaica's dusty roads make a clean, properly fitted air filter even more important.

Cleaning a MAF sensor

1. Disconnect the battery or the sensor connector.

2. Remove the sensor carefully from the intake.

3. Spray it only with a dedicated MAF sensor cleaner.

4. Never touch the sensing wires or element. They're very delicate.

5. Let it dry completely before refitting.

Don't use carburettor cleaner or brake cleaner, which can damage the sensor.

When cleaning isn't enough

If symptoms continue after cleaning, the sensor may be faulty, or there may be an air leak between the sensor and the engine. A leak lets in air the sensor never measured, causing a lean mixture. We check the intake hoses and clamps as part of the diagnosis.

Prevention

Replace your air filter on schedule, make sure it's seated properly, and avoid over-oiling aftermarket filters.

Need help with this? RCJ Mobile Mechanics comes to you in Portmore, Spanish Town, Kingston, St. Andrew and across St. Catherine. Call or WhatsApp (658) 207-6565 or book a mechanic online.