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Denso A/F Sensor has no Heat Shield

Discussion in 'Gen 2 Prius Technical Discussion' started by erkq, Mar 25, 2023.

  1. erkq

    erkq Junior Member

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    The Bosch A/F sensor has the dreaded heat shield that makes getting a wrench on it so difficult. The Denso does not. Other than that they are identical. The Denso's part number shows a picture with a heat shield on their web site. Can I use the Denso that has the same part number but no heat shield? See the attached pic. The Denso is on the right.

    Thank you!
     

    Attached Files:

    #1 erkq, Mar 25, 2023
  2. mr_guy_mann

    mr_guy_mann Senior Member

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    I install many A/F and O2 sensors on many different cars. None of them have the heat shield, and they all work fine.

    If the Denso unit is the correct listing for your car, then install it and don't worry about it.

    Posted via the PriusChat mobile app.
     
    #2 mr_guy_mann, Mar 25, 2023
    erkq and Tombukt2 like this.
  3. ChapmanF

    ChapmanF Senior Member

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    I'm not sure whether that collar was supposed to be a heat shield or some tamper-resistant feature (which, like other tamper-resistant features, tends to hold you off right up to the moment you go to Harbor Freight and buy the tool that fits it).
     
    #3 ChapmanF, Mar 26, 2023
  4. erkq

    erkq Junior Member

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    My hero, Harbor Freight, doesn't have the right tool. It needs to be short enough to not hit the transmission and thin walled enough to fit in the shield. Guys were taking standard O2 sensors and grinding their walls down to fit, an enormous amount of grinding. The proper tool is a specialized Toyota part which lends credence to your "tamper-resistant" theory. So in goes the Denso! Thanks!

    BTW, I ended up not being able to expose the hex nut enough to grab it with a hex socket. So I used a small pipe wrench. That made removal so easy! Worked like a charm. You still need to get rid of enough of the shield to be able to grab the sensor's body with the pipe wrench.
     
    #4 erkq, Mar 26, 2023
  5. ChapmanF

    ChapmanF Senior Member

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    Schley makes a suitable tool; there have been other threads discussing it. But not quite as convenient as finding something at Harbor Freight.
     
    #5 ChapmanF, Mar 26, 2023
  6. erkq

    erkq Junior Member

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    Hopefully this car will die before I have to do THIS again! :) I did read a lot of threads here and elsewhere. I never got reference to the Schley tool. So thanks for that.

    What I did get was this replacement is a total PITA. No one had the shroud-less Denso or had even heard of it. So hard is what I was expecting. Really... as it turns out... not so bad.
     
    #6 erkq, Mar 26, 2023
  7. erkq

    erkq Junior Member

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    FWIW, I had a P0138 error which a downstream O2 sensor replacement didn't fix. Add me to the group that fixed it by replacing the upstream sensor. No more check engine light!
     
    #7 erkq, Mar 30, 2023
  8. douglasjre

    douglasjre Senior Member

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    Where r u located?
     
    #8 douglasjre, Mar 30, 2023
  9. erkq

    erkq Junior Member

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    Nor. Cal. near Santa Rosa. All the way across the country.

    I see we had some common interests when I was younger, though I was nowhere near as advanced... just a hobby. I used to drag and bracket race. I loved bolting ATR's "go fast" parts onto Buick's Turbo-6 back in the 80's and 90's. I had 4 of those. I also drove on the local road racing tracks. Fun times.

    You look like an interesting guy to know... funny who pops up in PriusChat.
     
    #9 erkq, Mar 31, 2023
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