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Mass Airflow Sensor Service

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by ednorton, Nov 14, 2021.

  1. ednorton

    ednorton Junior Member

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    Hello, Have around 119,000 on a 2012 v. I don't drive in extreme conditions. Would it be time to service the MAS? Not getting any maint. lights, car performs normally. Since I don't see it as a regular maintenance item i am curious if this should be done. THX!
     
  2. QuarterMileAAT

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    Yes. Will cost you $7 for the sensor cleaner. 1 minutesof active engagement to remove the sensor. 1 minute of applying the cleaner. 15 minutes for the sensor to dry. Finally another minute to re-install the sensor.

    In other words, it is a no-brainer.
     
    Threej and ednorton like this.
  3. JC91006

    JC91006 Senior Member

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    There is no service schedule for the MAF sensor, if nothing is wrong with your car, don't go out and specially service it. You can create problems by servicing things that aren't causing any issues with your car.

    Good example I'm going to provide you is one of my friends decided to change their spark plugs at 60k miles, when it's not due until 120k miles. Just for fun, he did it on a weekend. Fast forward to 100k miles now, he broke down while on a roadtrip to another state. The reason for the breakdown, the spark plugs were not installed correctly and came loose. Cylinder 2 spark plug completely came off and the tip exploded off the plug.

    This break down including towing cost him over $1000 to replace all plugs and coils. So best not to mess with things when your car is running perfectly.
     
  4. Colorado Boo

    Colorado Boo Active Member

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    JC: Sounds like your friend needed more OJT for the spark plug job! (But I agree, if it's an iridium plug doesn't need to changing until 10-years or 100,000 miles.) Ouch, what a nightmare!!

    I just did a MAF Sensor and throttle body cleaning on my daughter's Mazda Saturday...it's a 2016 with 63,000 miles. SUV runs fine but it's part of my maintenance schedule. (Cleaned every 25,000 miles) Many vidoes on how to do that but here's some tips:

    -Only use "MAF Sensor Cleaner" on it and you have to remove it to do it good (two little screws and you disconnect it). Spray 3-4 times but don't touch the wires/elements and let dry well before putting back in.

    -Throttle Body: Disconnect negative battery terminal before starting. Easy to get to when you remove the inlet hose. Only use Throttle Body cleaner and a rag, not paper towel and spray it on the rag and gently clean all around the butterfly valve. You can slowly push in on the butterfly the stick you finger with the wet rag to clean all in there...it'll be pretty black so continue until the rag is clean and clean both the wall and the edges of the valve. I hold it open with the rubber end of a small screwdriver. Never spray the cleaner inside a throttle body unless it's removed from the vehicle. (If you do remove it, you'll, first, need to buy a new gasket to replace the old one...I rarely remove them for cleaning.) Also if you remove it you'll need to clamp down the coolant lines else they'll leak all over the place.

    The reasons for disconnecting the battery is because a clean MAF sensor will change the computers settings for it so just helps it reset faster. If it's really dirty expect the car to idle/run strange for the first 30 minutes or so of driving. Also, moving the butterfly valve around can effect the computer so it's best off. (And never move it around fast...slow and easy is what I was taught, it has an electric motor the computer controls.) And, again, nothing that can scratch inside of there.
     
  5. Peter123

    Peter123 Active Member

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    MAF sensor cleaner is out of stock in all my local auto parts stores. They tell me that containers of the stuff are sitting in ships off of the California coast. I went digging in my garage (mess) and found an old can that still had some pressure. So all wasn't lost.
     
  6. QuarterMileAAT

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    You can try Walmart too. Then of course there is Amazon.
     
  7. Ed Beaty

    Ed Beaty Active Member

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    "So best not to mess with things when your car is running perfectly."

    Or, if you must 'mess with things', mess with them correctly...