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Fuel - Air sensor debacle, please assist.

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by HellOnAStick, Mar 7, 2018.

  1. HellOnAStick

    HellOnAStick Junior Member

    Joined:
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    Location:
    South Lake Tahoe
    Vehicle:
    2008 Prius
    Model:
    ----USA----
    So, 2008 Prius is finally throwing codes. Take it to dealer, they say 1400 to replace oxygen sensor and fuel/air sensor. I feel this is the ''auto-da-fe'' as it were. Watch youtube vids. Buy Denso replacements. Replace downstream 02 sensor (denso universal) splice wiring. Encounter issue where the %&*# O2 sensor socket won't fit the heat shielding on the fuel/air sensor (upstream). Try to start the car. Car fails to start. Red triangle of death! Again, I search the internet for answers. Possibly a fuse, probably should have disconnected the 12v battery before mucking about with wires. Will check fuses tomorrow. But! What about the upstream sensor?! How in hell can I get it off? tried just turning the end of the sensor, it just spins. Tried a 7/8 socket, won't reach. Tried standard O2 sensor socket, walls of the socket are too thick. One youtuber ripped the shielding free and somehow made it work from there. I'm tempted to attempt same. Please save me. lol.
     
  2. exstudent

    exstudent Senior Member

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    Location:
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    Vehicle:
    2007 Prius
    Invest in proper tool(s) and the factory service manual; apparently you have neither.
    Get the factory service manual from Toyota's TIS (Technical Information System) via the 2-day subscription ($15).
    Toyota - New Subscription

    How to convert CHM to PDF
    Toyota TIS download tips | PriusChat


    SST (Special Service Tool) 09224-00010 is needed; search this and you should be able to find a compatible tool.

    Youtube is good when the repairs are done correctly. Unfortunately too many yahoos and a lot of misinformation out there. Monkey see, don't always monkey do.
     
    Dxta and HellOnAStick like this.
  3. HellOnAStick

    HellOnAStick Junior Member

    Joined:
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    Vehicle:
    2008 Prius
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    ----USA----
    Understood, however, I don't have too much in the way of time. Looks like I'll be scrapping that shielding after all, if possible. While I understand the value of manuals, and I actually have used the FSM in the past, I really didn't think it was necessary for something this elementary.
     
  4. voltech444

    voltech444 Junior Member

    Joined:
    Oct 2, 2016
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    Location:
    Pontiac, MI
    Vehicle:
    2006 Prius
    Model:
    Two
    I just started a similar thread yesterday: O2 Sensor Troubles | PriusChat

    I also made a video for the upstream O2 sensor:


    Yes that heat shield around the sensor is a biatch, what I did was I took a 22mm crowfoot O2 sensor wrench, and I ground it down on a bench grinder. Keep a little cup of water next to u so u can cool down the socket while gridning. I had to grind it down pretty thin to get it to fit, and it worked, it did take a good amount of torque to break it loose and i was afraid the socket was about to explode. Something that I was doing wrong, idk exactly how to explain this using only words, but the way the crowfoot socket works when coming at it from the opposite side (you'll see what im talking about, i think i mentioned this in the video) you have to set your ratchet to tighten, you will be turn it like your tightening it but because of the way the crowfoot works u need to turn it the opposite direction, I was getting super pissed when it wouldn't break loose and if i kept pushing harder something would've broke or stripped, and then I looked at it more and i was like oh crap i need to set my ratchet to tighten to make the crowfoot loosen.
     
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  5. PTrout

    PTrout New Member

    Joined:
    Oct 8, 2020
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    Location:
    Las Vegas
    Vehicle:
    2007 Prius
    Model:
    II
    Auto Zone will "rent " the socket set for $32. When done return it and get a full refund. Harbor Freight also has them.
    It is a struggle to get the socket in there but it is possible.