Chevy Silverado and GMC Sierra Forum banner

How to Inspect and Clean a Mass Air Flow Sensor (MAF)

272K views 70 replies 46 participants last post by  Chevy7 
#1 · (Edited by Moderator)
Cleaning a MAF is one of the easiest things you can do to keep your vehicle idling and running smoothly. Generally, this is a novice level activity. The only thing that could make it difficult is if your particular MAF is located in a hard to reach area. I have always done this at a frequency of every other oil change, or every 10,000 to 12,000 miles.

What is a MAF?
The Mass Air Flow sensor is used to measure the amount of air entering the engine. This measurement is used by the engine computer or ECM to calculate proper amount of fuel injected into the cylinders in order to provide optimum combustion and low emissions.
Problems with Mass Air Flow sensors are common. Bad or contaminated Mass Air Flow sensor can possibly cause a wide range of various vehicle driveability problems such as stalling, especially when the engine is cold, misfiring, poor acceleration, etc.
In addition, a problem with the Mass Air Flow sensor often causes the "check engine" or "service engine soon" light in the vehicle instrument panel to illuminate.

How to Clean a MAF:
1. Buy a quality MAF cleaner. DO NOT use carb or throttle body cleaner, or any other solvents. As you will see, the MAF is a very sensitive part. Use only the approved solvent, and follow the directions on the can carefully.
CIMG1334.JPG


2. Open the hood of the vehicle.
CIMG1335.JPG


3. Locate the air filter housing. Usually, the MAF will be just "downstream" of the air filter, in the tube that carries air to the resonator and throttle body. You can see the MAF and it's related connector circled in this photo:
CIMG1336.JPG


4. Release the electrical connection on the MAF. There is a small tab that holds the connection in place.
CIMG1337.JPG


5. Using either a phillips screwdriver or a torx bit (my truck uses a T-10 torx), unscrew the screws holding the MAF in place.
CIMG1338.JPG


6. Make sure you know what direction the MAF is in place. Often, you will see an airflow arrow to help you. Make sure you are able to put the MAF back in the same direction later!
CIMG1340.JPG


7. Carefully remove the MAF. Note the thin wires that run across the MAF. When this unit is in operation, those wires get hot. Simply stated, the rate (resistance) at which the wires heat or cool gives the computer the inofrmation about how much air is moving across them, and into the engine. When they are dirty, your ECM cannot correctly determine the airflow.
CIMG1341.JPG

CIMG1342.JPG


8. Set the MAF on a paper towel or clean shop rag. Follow the directions on the can to spray the solvent on the MAF. Be careful that the spray tube or other things do not bump the MAF. Again, the wires are fragile. Spray the MAF from all sides, and then allow it to dry. Make sure the MAF is fully dry before reassembling.
CIMG1345.JPG


9. Reassemble the MAF. Ensure you install it in the correct direction. Also ensure the wire harness is re-connected.

10. It is not required, but I also ensure that I disconnect the battery while I complete this procedure. Doing so will reset your ECM, and will take into account this cleaned MAF!

You did it! Congratulations!
 

Attachments

See less See more
9
#2 ·
Very well done like all the info. thanks

I will bring up what I know is that your MAF also controls the pressures inside the transmission. The more engine torque = transmission pressure needed. MAF not reading right may burn up your transmission. Keep them clean and don't add extra K&N oil.
 
#4 ·
There is no screen that I know of. Should not need one, since air has just passed through the filter, anyway.
I still would not use brake cleaner. Maybe a throttle body/carb cleaner...but never on the MAF, as you said.
 
#5 ·
mine has a screen in the beginning of the tube right after the air box. when I removed the air box to replace a light i touched it and it left a finger print on it because it was so dirty. I bet my MAF is just as dirty. Ill take a pic of it tomorrow. my box and tube are different then yours. When using the MAF cleaner do you use the hole can? if not ill clean the screen with that. Maybe that screen it a squirrel catcher.
 
#6 ·
Great article Eric.

Will definately put this on my to-do list when I finish this deployment.

"I love the smell of axle grease in the morning.... It smells like victory."--Me
 
#8 ·
Kind of like a TB spacer for your MAF, huh Gordon? Are there after market screens that straighten the air better than others, so we can get 5-10 additional MPG's? :)
 
#9 ·
Those spacers add length to your intake which (in theory) is supposed to increase torque at lower RPM's. I've yet to see anyone with proof they work on newer trucks. High performance screens? Maybe we can start a business and sell them in different colors. :D
 
#10 ·
Great article, Eric. I've never done that before, and I'm guessing my truck hasn't had it done in a while... well, I'll add it to my to-do list!
 
#11 ·
lzn197 said:
Those spacers add length to your intake which (in theory) is supposed to increase torque at lower RPM's. I've yet to see anyone with proof they work on newer trucks. High performance screens? Maybe we can start a business and sell them in different colors. :D
Back when the injectors were in the throttle body, the spacers gave more time for fuel to atomize, increasing burn efficency. Doesn't do a dang thing with todays multiport injection motors.
 
#13 ·
Hartski said:
lzn197 said:
Those spacers add length to your intake which (in theory) is supposed to increase torque at lower RPM's. I've yet to see anyone with proof they work on newer trucks. High performance screens? Maybe we can start a business and sell them in different colors. :D
Back when the injectors were in the throttle body, the spacers gave more time for fuel to atomize, increasing burn efficency. Doesn't do a dang thing with todays multiport injection motors.
Well, we'll see- my throttle body spacer should come tomorrow or Monday...
 
#15 ·
Thanks for sharing! I did not know about that.
 
#16 ·
Hi Guys.

new to the forum, but not new to trucks!

like someone else said earlier, those screens are to eliminate air turbulence and stratify the air while passing over the MAF. this reduces stress on the MAF wires, and also provides consistent air over the wires to reduce fluctuations in the sensor output. it does have a function unlike someone earlier had said. remove at your own risk.

cheers!

Stan
 
#18 ·
I cleaned my MAF just yesterday and it really is insane how different your engine responds after cleaning the MAF. Advanced had a special (buy MAF cleaner get throttle body clean for free) so while cleaning the MAF I also cleaned the throttle body as best as I could with it still attached. Cleaning around the seals of the butter fly valve has improved response time and even my shifting. I highly suggest people do this every so often to keep everything running smoothly and the way it should.
 
#25 ·
Well, you have a 2000 truck, and mine is a 2010. They could look quite different. The general concept should be right, though.
 
Top