What To Do After Replacing Mass Air Flow Sensor?

The MAF air mass sensor is one of the key engine components in vehicle technology.

It is located between the air filter and the engine’s intake manifold with the participating task in the fuel injection process. When this part fails, it leads to miscalculation, causing severe damage over time. You will need to replace the sensor in this case.

So, what to do after replacing the mass air flow sensor? How to change a mass air flow sensor? The following article will help you answer this question in detail.

What To Do After Replacing Mass Air Flow Sensor

What To Do After Replacing Mass Air Flow Sensor?

Here are the steps to follow on how to disconnect the mass air flow sensor. Let’s check them all now for details!

Disconnect the battery

After replacing the air flow sensor, you need to perform a battery disconnect to complete this process. Disconnecting the battery will take about 15 minutes. To do so, follow the steps below:

  • Step 1: You must prepare safety kits such as gloves and goggles. Then start turning off the engine.
  • Step 2: Find the battery-negative terminal. If you find it difficult, you can ask a mechanic. They will help you locate the exact location.
  • Step 3: Use a wrench to loosen the nuts of the negative terminal.
  • Step 4: Remove all negative connection points
  • Step 5: Repeat the above process with the positive terminal of the battery
  • Step 6: Although the battery is completely disconnected, you should still remove it from its original position. It will help you to check the current battery’s health at the same time.

The whole process of disconnecting the battery will help you to do a factory reset. It also helps to remove all old parameters. The system will now start recording new data with the recent change.

Perform regular maintenance

The MAF air flow sensor system only sometimes appears in the car maintenance list. However, you should pay attention to this part because it will likely be degraded after a period of use.

MAF sensor inspection and maintenance take only a few minutes. If you are still wondering about that, you can refer to the steps below:

Step 1: Find the air intake system

The location of this part on vehicles will be different. Therefore, you should use the vehicle repair manual in this case. The book not only helps you locate, but it also helps you make repairs such as bypassing the knock sensor

Step 2: Find the MAF sensor in the air intake system

Conventional air intake systems are made of metal or plastic. When you disassemble this part, you will find the MAF sensor between the filter and the motor. Then, you should check to see everything when removing the mass air flow sensor.

Step 3: Clean the sensor

To do this, follow these small steps:

  • Start the car engine.
  • Use the cleaner on the engine. When your engine components shut down, it’s completely normal. You don’t need to worry in this case.
  • After each spray, use your hands to wipe all the water, so your engine does not run.
  • When you do step 3, you may see the code P2197 or OBD2. It is a sign that too much air is entering the engine. This large quantity does not match the current electrical engineering fuel supply.

However, you do not need to worry too much about this phenomenon. Since those codes appear during the cleaning process, it’s safe for you to ignore these 2 codes for a while.

Step 4: Reassemble the air intake system

In this step, install the air flow sensor in the original position. When the filter is too dirty, you should replace it with a new one. Then, use the car repair manual to assemble the vehicle parts in the correct order.

Step 5: Use the scanner to remove the code

In step 3, 2 sets of warning codes warn of too much air in the engine. Now use the scanner to remove the code.

When does the MAF sensor fail and need to be replaced

When does the MAF sensor fail and need to be replaced?

The MAF air flow sensor tends to degrade in performance after a period of use, especially with Toyota models. Therefore, inspection and replacement, in this case, are essential. 

To make this work, you must know when your MAF sensor is failing. The following section of the article will provide you with detailed indications that it is underperforming:

Engine lights

The rotating machine’s light strongly indicates that the MAF sensor is not working correctly. You may notice a faint light coming from your vehicle and conclude that the MAF sensor is underperforming in this case.

Jerk when accelerating

In addition to the headlights, you may find that your MAF sensor is having trouble when it comes to jerking when accelerating. Unusual jerking or sluggishness when accelerating indicates your car is having problems.

Some drivers will ignore this phenomenon. However, if you experience prolonged abnormal jerking, you should take your vehicle to a service center. Most likely, the MAF sensor is working poorly. It will lead to negative consequences in the long run if you don’t fix it.

Wrong run

Wrong runs are the next sign that the sensor is doing poorly. Because the MAF department plays a crucial role in managing the transmission, engine, and other systems.

Wrong running can come from PCM’s misunderstanding about the amount of fuel supplied to the engine. It’s too little or too much. At that time, the throttle part will lose control, and you will not be able to run safely in this case.


If your car stalls many times, it is a sign that there is too much air inside the engine, but the fuel ratio is too small. Over time, dirt will build up on the MAF’s wire. At that time, the combustion process inside the engine will begin to degrade, and you will need to seek the help of professionals.

Black exhaust

The next sign that the MAF sensor is having problems is black exhaust. While it doesn’t just come from the MAF sensor, you shouldn’t skip checking this part. When a position fails, the engine can miscalculate the amount of fuel. It will not be able to provide accurate data for fuel injection.

Difficult to start the engine

When you find it challenging to start the engine, it could be a sign that the MAF sensor is having a problem. 

Because, at this time, the air/fuel mixture ratio tends to be out of balance. When it does, it can make it difficult for your car to start or shut down immediately after starting.

How much does MAF sensor replacement cost

How much does MAF sensor replacement cost?

Airflow sensor replacement costs depend on the location, vehicle inspection, and labor costs of the mechanic you service. 

The total cost of replacing this part will range from $120 to $200. It includes both the labor cost and the cost of the parts you need to buy.

Additionally, some sensors cost upwards of $400. The cost for the mechanic will range from 20 to 50 dollars. It may be higher if the mechanic is more experienced and your car model is on the new version.


Does a MAF sensor need to be calibrated?

You will need to recalibrate the MAF sensor when it fails. Sometimes, you will need to replace this part after a period of use.

Should I disconnect the battery after changing the MAF sensor?

After replacing the airflow sensor, you need to disconnect the battery for 15 minutes. This process will go through 6 steps; you can refer to them at the top of this article.

What happens if you put the wrong MAF sensor in your car?

When your MAF sensor has a problem, you can recognize it based on the following signs:

  • Wrong run
  • The car is not loaded
  • Black smoke appears on hardlines
  • Abnormal jerking condition

This time, taking the car to the service center is necessary. They will help you clean or replace the sensor if necessary.

How do you reset a mass air flow sensor?

You can reset the mass air flow sensor installation by disconnecting the battery. This process will not take about 15 minutes. It takes work for you to do it yourself. Therefore, you should seek the help of professionals.


Hopefully, the article will help you answer the question: “What to do after changing mass air flow sensor?“. After replacing the sensor, you need to disconnect and service it regularly. It will help you check your sensor’s performance and spot problems quickly.

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