Your truck’s mass airflow sensor is critical to your engine’s health and can affect how it starts, runs, and how the truck uses fuel.
Here we’ll look at what it is, the symptoms of a faulty MAF, answer some helpful questions, and learn how to clean the mass airflow sensor in your Chevy Silverado.
Mass airflow sensor explained
The mass airflow sensor and your engine’s computer measure airflow as it moves across the sensor to regulate the air/fuel mixture.
The sensor notes changes in air density when it changes with the altitude and temperature to ensure the correct mix is always present. The MAF is found in the throttle body and alerts you with the check engine light.
Symptoms of a Faulty Mass Airflow Sensor in Chevy Silverado
1. Check engine light
The check engine light will be the first sign that something is wrong. The check engine light illuminates when the sensor tells the computer the air/fuel mixture is incorrect. Those who own a code reader will be able to retrieve the code.
2. Slower acceleration
The car won’t accelerate as quickly as it used to. Slow acceleration happens when the spark from your spark plugs is doused by running rich, which means too much fuel and not enough oxygen.
3. Rough idling
As a car idles, it is quiet, and the idle is barely noticeable. When the vehicle runs rough, you can feel it idle. The rougher it idles, the more you feel it. Rough idling is a sure sign that the MAF sensor is not working.
5. Difficult starting
There needs to be the perfect air-to-fuel mix as you start the car for the engine to turn over. If the vehicle is not starting as it should, a bad MAF sensor may be affecting the air-to-fuel mix.
5. Jerky driving
Too much oxygen and not enough fuel will starve the engine and create jerking as you drive. It can start as you move the vehicle or happen after a period of driving.
6. Poor fuel consumption
Poor fuel consumption is expensive and means you are using more fuel than usual. If you were getting 38 miles per gallon and now, you get 32 miles to the gallon, the mass airflow sensor may be the culprit. The car is inefficiently burning the gas.
7. Engine misfiring
Misfiring is usually caused by a cylinder that is not correctly burning fuel. The engine needs combustion, the perfect fuel-to-air ratio, and ignition to start. You hear a misfire when one of these three things is missing, and one of the cylinders doesn’t ignite. A misfire is a “boom” similar in sound to a gunshot.
8. Blackish smoke from the tailpipe
An engine that runs rich or too heavy on fuel burns off the excess, and black smoke is the result. A faulty mass airflow sensor is usually the cause. This is not good for the catalytic converter, which is expensive to repair.
How to Clean the Mass Airflow Sensor in a Chevy Silverado
- T15 Torx screwdriver
- MAF CRC spray cleaner
Step 1 – Find the mass airflow sensor
The mass airflow sensor sits between the air inlet hose and the air filter (see the image below).
Step 2 – Detach the MAF sensor connectors
Make sure the car is off and the engine is not hot. Attached to the intake hose is a small black box with an electrical connector that plugs into it. There are two tabs on the connector that you press down on to release the connector from the mass airflow sensor to pull it out. On the opposing corners, there are two Torq screws. Using the T15 Torq screwdriver, unscrew and remove the screws, then remove the MAF sensor from the air intake hose.
Step 3 – Clean a dirty mass airflow sensor
You’ll need to see the wires in the sensor, so place it in a container (cup) or on a surface you can do that. You want to clean the wires well.
Spray the CRC MAF cleaner on the wires to clean the sensor on the inside and every inch of the wires. You will need to clean the whole wire. It should be completely dry before reinstalling.
Step 4 – Reinstall and test drive
Once the sensor is dry, the mass airflow sensor goes back into the air intake hose. Replace the screws and retighten them. Lastly, reattach the electrical connector.
You’re ready to drive the truck and ensure the sensor is working properly.
Helpful tips for the sensor removal
- Disconnecting the battery will turn off the check engine if the dash light is lit
- To prevent damaging the sensor, use a cleaner specifically made to clean a MAF sensor
- Handle the sensor carefully. Sensors are fragile. If it is damaged, you will need to buy a replacement
How often does an airflow sensor need cleaning?
As long as the filter is doing its job and you aren’t having problems related to it, you can clean it routinely as you change the air filter.
If one of the symptoms arises, you can give it an additional cleaning. Grime and debris on the engine can build up quickly and affect the sensor.
Can you drive with a bad mass air flow sensor?
Can you, yes. Is it a good idea, no? Driving with a faulty sensor can cause the car to run rich, gum up the valves, and create numerous problems. It is easier and makes more sense to clean or replace the sensor than incur bills for issues you could have avoided.
Should you clean a MAF or replace it?
Most of the time, the mass airflow sensor is just dirty, so a good cleaning is all it needs. You should replace the sensor if there is an electrical or mechanical failure.
Does a car run better with an unplugged mass airflow sensor?
If your mass airflow sensor is unplugged, the car’s computer will incorrectly read the data and wrongly adjust the air-to-fuel mix.
It will also register that the sensor is gone and put the vehicle in limp mode. While you can still drive the car, it won’t perform as well. If you are getting more power in limp mode than usual, there is a significant failure in the mass airflow sensor.
Chances are, if you clean the sensor, it won’t help. You will need to replace the sensor at this point.
Does the battery need to be disconnected when changing a MAF?
You won’t need to disconnect the battery to clean it, but it is an excellent practice to get into. You can be shocked when working on an engine, just like you can with any electrical appliance.
Does it take long for a mass airflow sensor to reset?
It takes 10 to 15 minutes to reset the mass airflow sensor. You can disconnect the wire harness or disconnect the battery, whatever way is easier.
Disconnecting the electric connector when cleaning the sensor also resets the sensor. Never reset the sensor when it is dirty or not working correctly.
How can a mass airflow sensor mess up your transmission?
It’s not likely, but it’s possible for the loss of power caused by the faulty sensor to cause rough shifting or gear changes.