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MAF sensor not cleaning up?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by cloudy, Jun 15, 2024 at 2:31 AM.

  1. cloudy

    cloudy Junior Member

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    2008 Gen 2 200,000 km odo

    I've been getting 5.0L/100km (47MPG), but a friend who has the same car (300,000km odo) is getting 4.4L/100km (54MPG) under very similar driving conditions.

    I decided to try clean the MAF sensor as others have noted improved economy after cleaning this sensor.

    I used isopropyl alcohol and an air puffer. Photos below are after cleaning. The temperature sensor part (second image) came out noticeably cleaner. One of the two hot wire sensors inside (upper image) would not clean up (see upper image). I decided not to touch with anything other than alcohol and air. It looks like there is corrosion, something sticky or melted on this one wire.

    Has anyone else had this issue? Will the specific MAF spray cleaner work better for this? Shops are closed so I decided to re-install as is.

    I also changed the engine air filter, but reading the forums this apparently will not affect economy.

    thanks!
    20240615_150705.jpg 20240615_151257.jpg 20240615_151315.jpg
     
    #1 cloudy, Jun 15, 2024 at 2:31 AM
    douglasjre likes this.
  2. Tombukt2

    Tombukt2 Senior Member

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    I wouldn't be able to keep my pic or little flat miniature scraping tool or something to try and knock that off see if that's possible of course I also have five or six vehicle sitting around here in case I break it I can take another one off I've never seen that bad of rust and crud or whatever that is built up on one of those pieces of the flat metal
     
    #2 Tombukt2, Jun 15, 2024 at 9:20 AM
  3. mr_guy_mann

    mr_guy_mann Senior Member

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    Yes, MAF cleaner spray will work better.
    See what you get with that. The sensing elements are fairly fragile. Sometimes I have to clean "more aggressively", but you can damage them.

    Here's what they should look like.

    After cleaning, you can check the MAF sensor readings in ECM data if you have a scantool.
    clean_maf.JPG

    Posted via the PriusChat mobile app.
     
    #3 mr_guy_mann, Jun 15, 2024 at 10:28 PM
  4. mr_guy_mann

    mr_guy_mann Senior Member

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    Here's MAF values from my 2006 taken under various running conditions - "near" sea level altitude. Screenshot_20240615-223147.jpeg

    Posted via the PriusChat mobile app.
     
    #4 mr_guy_mann, Jun 15, 2024 at 10:34 PM
  5. cloudy

    cloudy Junior Member

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    Thanks for your response, I will buy the proper cleaner and see how that goes.

    When you say "clean more aggressively", how do you do this? Are you touching any tool to the hot wires inside the sensor?

    I do have and OBD2 plug and have used the Dr Prius App (free version) in the past. Can this be used to look at ECM data, or what did you use?
     
    #5 cloudy, Jun 16, 2024 at 6:39 PM
  6. cloudy

    cloudy Junior Member

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    I used electronics contact cleaner with a straw and this got the sensor really clean. I did not have to touch the wires, just got the straw close and blasted with the cleaner.

    I have not tried connecting to ECM yet but I'm not sure if this will be necessary. I'll see if the economy improves now.

    Thanks again for your help.

    20240617_171049.jpg
     
    #6 cloudy, Jun 17, 2024 at 6:37 AM
  7. mr_guy_mann

    mr_guy_mann Senior Member

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    #7 mr_guy_mann, Jun 17, 2024 at 11:32 AM
  8. mr_guy_mann

    mr_guy_mann Senior Member

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    If needed, I use a "fuzzy craft stick" (pipe cleaner to us old timers) soaked in MAF cleaner as a brush. It will fit between the two elements. I only let the "bristles" contact the sensing elements. I do not use anything else (no cotton swabs). Make sure no "fuzz" is left behind.

    Use at your own risk. YMMV.

    If you want a free OBD2 app, try Torque - should work with your adapter (I think it's android only).

    Posted via the PriusChat mobile app.
     
    #8 mr_guy_mann, Jun 17, 2024 at 12:26 PM
  9. ChapmanF

    ChapmanF Senior Member

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    There are some electronics contact cleaners that leave a residue behind to protect or lube the contacts. I don't know about the specific cleaner you used. But you might want to re-do the job with some MAF cleaner just to make sure there's nothing left there that might cook on or cause flakiness later,
     
    #9 ChapmanF, Jun 17, 2024 at 1:20 PM
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