8 Dirty Mass Air Flow Symptoms and Replacement Cost

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maf sensor symptoms

The mass air flow sensor is an integral part of most car engines to run properly.

Okay, but what does the mass air flow sensor actually do?

The MAF measures how much air enters the car engine and sends this information to the engine control unit, which controls how much fuel the fuel injectors should inject.

A faulty MAF sensor, as you might expect, is a major pain in the neck. Furthermore, if left unchecked, the problem may damage other components of your car, such as the catalytic converter. As a result, it’s critical to correct any concerns about your MAF right away.

The most common symptom of a bad mass air flow sensor is engine performance issues while you also have a check engine light. A loss of power, rough acceleration, hard starting situation, misfires, or black smoke from the exhaust pipe are just a few examples of this kind of performance issue.

In this article, we will discuss the common symptoms of a dirty MAF sensor and how much they cost to get replaced.

How does a hot-wire air flow sensor work?

air flow correctly

A temperature sensor positioned near the hot wire monitors the air’s temperature. A small electrically heated wire (hot wire) is used in a hot-wire mass air flow sensor. The temperature of the surrounding area is measured by a temperature sensor that is linked to the hot wire.

When the engine is idling, a tiny amount of air circulates around the hot wire, so it takes a minimal electric current to maintain it hotm. When you press the accelerator pedal, the throttle opens, allowing more air to flow over the hot wire. The passing air cools down the wire. The greater amount of air that goes over it, the more electrical power is needed to keep it hot.

It’s important to keep the amount of air flowing consistent in order to maintain optimum efficiency. The amount of electricity generated is proportional to the rate of air flow. An electronic chip inside the air flow sensor converts the electric current into a digital signal and transmits it to the powertrain control module (PCM). The PCM uses the air flow signal to determine how much fuel to inject. The objective is to keep the air fuel ratio at an optimal level.

Bad mass air flow sensor symptoms

bad mass airflow sensor

There are many symptoms of a bad or dirty MAF sensor.

Check engine light illuminates

The MAF sensor may be responsible for increased engine noise and rough idling, as well as performance and circuit diagnostic trouble codes. However, fuel trim and misfire indications can all be linked to the MAF sensor. If you notice your check engine light is illuminated, you bring it to a mechanic.

Rough idle

It’s difficult to get a smooth idle without the correct quantity of fuel. The engine may not run properly while idling if you have a bad mass air flow sensor.

Bad fuel economy

Even a small amount of error by the MAF sensor might have an impact on fuel efficiency. If the engine control module (ECM) is faulty, it may add more fuel than necessary, resulting in poor gas mileage.

Black exhaust smoke

The ECM may sometimes be faulty, causing black smoke to emerge from the exhaust. When the air fuel ratio is overly rich, black smoke comes from the exhaust. This can overload the catalytic converter as well.

Hard starting

Engines run on more fuel while starting than when they are idling, but if the MAF sensor signal is skewed, the ECM may not be able to order enough fuel injection.

Loss of acceleration while driving

A faulty MAF sensor will result in an out-of-balance air fuel mixture. There are a lot of unusual issues with your vehicle if the air-fuel ratio is incorrect. Loss of acceleration while your driving can be one of these issues.

Rough accelerating

The ECM may be restricting injection due to MAF sensor issues if you’re having difficulties accelerating into highway traffic or passing.

Engine misfires

Misfires occur when one or more cylinders fail to combust the fuel. To burn the fuel successfully, the engine needs three elements: an appropriate air-fuel ratio, an ignition, and compression.

Many of the symptoms described above aren’t always caused by a bad mass air flow sensor. A vacuum leak, an obstructed air filter, restricted exhaust, a clogged catalytic converter or an abrasion on the intake tube can all mimic a bad MAF sensor; so eliminate those possibilities first.

How do you clean a dirty mass air flow sensor?

Cleaning your mass airflow sensor once a year, or whenever you change your oil, is usually a suitable idea. Cleaning it after changing or cleaning your air filter will save both time and money. Here’s how to clean your mass air flow sensor.

Step 1: Remove the sensor

To clean your mass airflow sensor, you must first remove it. This is accomplished by opening the air box in your car and plucking it out with a flathead screwdriver. When removing the sensor, avoid touching the wires at all costs. Even though they won’t electrocute you, the wires are fragile and tiny, and can run you upwards of $100 for a replacement.

Step 2: Clean the sensor

The most straightforward technique is to put your mass air flow sensor in a plastic bag filled with rubbing alcohol. Take the bag and move it about, making sure all of the dirt and grime is washed away from the sensor. Alternatively, you may purchase a specific mass airflow sensor cleaner at an auto parts store and spray it on your sensor; however, this is more expensive.

Step 3: Dry and reinstall the mass air flow sensor

Allow 20 minutes for the sensor to sit after cleaning it with either the cleaner or alcohol, then reinstall it in your car. Before it can be replaced in your vehicle, the sensor must be completely dry; otherwise, you risk damaging it. That’s all there is to it!

How much does it cost to replace a mass air flow sensor?

The average cost of replacing a mass air flow sensor is between $140 and $550, depending on the vehicle model and labor charges. A mass air flow sensor costs between $100 and $400 while labor costs $40 to $150.


Can you drive with a bad mass air flow sensor?

Yes, you can drive with a bad mass air flow sensor but not for very long. Driving too long with bad maf sensors can lead to serious engine trouble.

What happens if you drive with a bad mass air flow sensor?

A faulty MAF sensor can cause an excessive amount of petrol to be left in the combustion chamber, resulting in untimed detonations. You’ll notice this as a lack of driveability, such as delays or quick jerking motions, especially when driving up hills.

Can a mass air flow sensor mess up your transmission?

A failing air flow sensor can cause a variety of driveability issues, including a no-start, stalling, power loss, and sluggish acceleration. A malfunctioning air flow sensor may also affect the automated gearbox’s shifting pattern.

How often does a mass air flow sensor need to be replaced?

The MAF sensor needs to be replaced every 10,000 – 12,000 miles. Your MAF sensor’s life can be extended with regular maintenance and air filter replacement. A good rule of thumb is to go by the book every 10,000 to 12,000 miles. There is no such thing as an expiration date for a mass airflow sensor (MAF).

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