What To Do After Replacing Mass Air Flow Sensor (Avoid Problems Later)

Installing a new mass airflow sensor is only the first step in keeping your vehicle working properly. There are certain things that you should consider to ensure that the installation is done properly and that all of the components are working properly.

After you replace your mass air flow sensor, you should first clear all of the engine fault codes by idling the vehicle and removing the battery. Once you have done this, you should update the engine control module and replace the air filter. Finally, use a scan tool to clear any remaining engine fault codes and take your vehicle for a test drive to ensure it is running properly.

This guide will walk you through these processes so that you can rest assured that your newly installed mass air flow sensor is working properly.

The Basics Of A Mass Air Flow Sensor

The mass air flow sensor of your vehicle is a vital component that controls the electronic fuel injection system in your car. It is generally located between the air filter and intake manifold of the engine. The mass air flow sensor is responsible for measuring the amount of air that enters the engine.

If your vehicle features a hot-wire mass air flow sensor, it uses a small electrically heated wire to measure the temperature of the air entering your engine manifold. While the engine is idling, air will flow around the hot wire to keep it hot.

As you press the gas, the throttle will open up and allow more air to flow over the wire. As the passing air cools the wire down, more electrical current is necessary to keep the wire hot. This electrical current is proportional to the amount of incoming airflow.

Most mass air flow sensors utilize an electronic chip installed inside of the airflow sensor to translate electrical current into a digital signal that is then sent to the engine computer. The engine’s computer then uses the airflow signal to determine exactly how much fuel should be injected.

A properly functioning mass air flow sensor will keep the air and fuel ratios at the optimal level. These ratios help to alert automatic transmission systems when to shift gears. Problems with the mass air flow sensors can cause a range of different issues.

These issues stem from not being able to measure the amount of airflow correctly. This will cause the engine’s computer to potentially miscalculate the amount of injected fuel which will result in some serious issues with your vehicle.

These issues include drivability problems, trouble starting the car, and poor acceleration. This will often result in the check engine light coming on in your vehicle. Another noticeable issue that may arise is trouble with the automatic transmission shifting gears.

Your vehicle’s engine computer will log fault codes when encountering issues with the mass air flow sensor. This will be helpful when using a scan tool to determine exactly what the cause of the issue is. If you are having issues with your air flow sensor, then you will need to replace it.

Typically, a mass air flow sensor can be replaced for around $100 to $350. In some cases, the airflow sensor may be cleaned to fix any issues that it is causing. There are some things you should do after installing a new mass airflow sensor to ensure that it keeps working properly. These will be covered in the next section of this guide.

Steps To Take After Replacing Mass Air Flow Sensor

The following steps should be taken immediately after replacing the mass air flow sensor. This will help ensure that the installation was done correctly and that you will not experience any issues in the future.

Let Engine Idle For 30 Minutes

The first thing that you should do is idle the engine for at least 30 minutes. This will allow the mass air flow sensor to reset and reoptimize the air and fuel ratios. All you need to do is turn on your vehicle and put it in the park for at least thirty minutes or up to an hour.

Once you have done this, turn the vehicle off for a few additional minutes to ensure that the mass air flow sensor has had time to reset and recalibrate.

Remove Car Battery

You should remove the vehicle’s battery to ensure that the mass air flow sensor resets properly. This will also clear any store error codes that may be present in the engine computer’s memory.

You should disconnect the negative battery terminal and leave it disconnected for at least five minutes. Once you have done this, you should start the vehicle and let the engine idle for at least thirty minutes.

Clean Mass Airflow Sensor Switch

Next, you should clean the mass airflow sensor switch using some form of intake cleaner. This can be done by removing the air filter, though you should be sure to reinstall it as soon as possible. Your vehicle will typically lose power doing this process or your engine may stall temporarily after you spray.

These issues should resolve themselves after a short time after spraying all of the accessible sensor components. One thing you should be sure to do is to keep the fluid from entering the engine. This must be done carefully because it must be running while using the spray cleaner to ensure that it burns off with the gas.

In some instances, using an intake cleaner to spray your new mass airflow sensor may result in some form of error codes. These can be disregarded if you have just used intake cleaner to spray your air flow sensor, as they are most likely triggered by exposure to the spray.

Clear Engine Fault Codes

You should next clear any remaining engine fault codes using a scan tool. This should only be done after verifying that the mass air flow filter has been installed correctly. Once you have done this, all of the error codes that may have been present should disappear and not reoccur.

If there are still engine fault codes present after using the scan tool to clear them, there has likely been some issue with the installation. You will need to reevaluate the installation and inspect the mass air flow sensor for damage.

Update Software On Engine Control Module

The engine control module should be updated if your vehicle supports manual updating. The ECU is a vital part of your vehicle and controls the transmission, fuel consumption, and other vital functions. Not all vehicles will need to have the software updated for the ECU.

You should consult your vehicle’s manual for the exact method of updating your ECU and follow it if necessary. This will usually involve hooking your vehicle to a Wi-Fi connection to download and install the proper files.

Replace Air Filter

Once you have cleared the error codes and allowed your new mass air flow sensor to calibrate, you can replace the air filter. It is best to purchase and install a new air filter any time that you replace your mass air flow sensor.

It is important that you remember to install the air filter to avoid issues with your mass air flow sensor in the future. The air filter will keep debris from entering into your engine block and potentially damaging your vehicle’s internals.

Check Mass Airflow Sensor Is Working Correctly

Next, you should check the mass airflow sensor to ensure that it is working properly. You can do this by checking the sensor’s power feed. The process to do this has been listed below:

1. First, open the hood of your vehicle.

2. Unplug the mass air flow sensor electrical connector.

3. Set your DMM to around 20 volts DC.

4. Connect your multimeter’s red lead to the B terminal.

5. Connect the meter’s black lead to the ground pin on the sensor connector.

6. Turn the ignition switch to the on position but do not start the engine up.

7. Ensure that the meter is getting over ten volts.

If you do not have access to a DMM, there is a quick way that you can check that your newly installed mass air flow sensor is working properly. The method to do this without a DMM has been detailed below.

1. Engage the parking brake of your vehicle.

2. Set the transmission to park or neutral.

3. Start the engine and let it idle for a few minutes.

4. Open the hood of your vehicle.

5. Lightly tap on the mass air flow sensor and electrical connector with a screwdriver handle.

6. Wiggle the wires carefully.

7. If the engine begins to stall or the idle is upset, the mass air flow sensor is likely not installed correctly and will need to be adjusted.

It is important that you test your mass air flow sensor carefully as the electrical components can be a shock risk. If you are not comfortable testing it yourself, you should take your vehicle to a certified mechanic.

Road Test

Finally, a road test is necessary to ensure that your vehicle is driving normally. Simply start your car and take it for a quick drive to ensure that no new issues are present after installing your new mass air flow sensor.

After driving for a few minutes, if there are no noticeable issues, you can safely assume that your mass airflow sensor is working properly and the installation was successful.

Problems That Can Result From Not Following This Process

If you do not follow the process detailed above to ensure that your mass airflow sensor is installed and working properly, you could run into some serious issues. One issue that you may encounter is engine fault codes that are not cleared.

It could also cause engine problems that will affect how efficiently your engine operates, including low engine power or significant engine damage. Following the process listed above will help you avoid these issues and keep you from incurring any costly repair costs from an improperly installed mass airflow filter.

Conclusion

There are certain things that you should do after you replace your mass air flow sensor to avoid issues in the future. These include clearing the engine fault codes, cleaning the mass air flow sensor switch, and checking that it is working properly by taking a test drive.

Following these steps can help ensure that your mass air flow sensor will function the way it is intended. Failing the follow these steps can cause serious issues with your engine that could potentially result in costly repairs.

If you are looking to see what happens if you disconnect your airflow sensor, then make sure you contact a professional or do your research. You don’t want to be messing with something if you are unsure of the outcome it will have on your car.

If you are not comfortable carrying out this process by yourself, you should take your vehicle to a mechanic to be serviced. They will be able to ensure that your mass air flow sensor is working properly and give you peace of mind while driving.