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P0031 code

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by priusde, Aug 27, 2017.

  1. priusde

    priusde Junior Member

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    I have the P0031 code and from what I've found points to the A/F ratio sensor Bank 1 Sensor 1. I found the part number I need is Denso 234-9090. Is this something I could do myself or is this a job left to the dealer due to the location of the sensor not being very accessible? Would I need special tools?
     
    #1 priusde, Aug 27, 2017
  2. NutzAboutBolts

    NutzAboutBolts Senior Member

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    The Air fuel ratio sensor heater is by the EGR pipe and cooler. You will need an O2 sensor socket to remove the sensor though.
     
    #2 NutzAboutBolts, Aug 27, 2017
  3. priusde

    priusde Junior Member

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    Do I follow your EGR pipe cleaning video to access?
     
    #3 priusde, Aug 27, 2017
  4. NutzAboutBolts

    NutzAboutBolts Senior Member

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    you can try, I haven't taken a look at it yet.
     
    #4 NutzAboutBolts, Aug 27, 2017
  5. m.wynn

    m.wynn Senior Member

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    It's on the exhaust manifold. You can see it by standing at the passenger side front fender, putting your face behind the engine coolant bottle and peeking behind the top end. Flashlight helps. Follow Nutz about Bolts video (spark plug change, maybe?..) that shows removing the wiper cowl and access becomes about as easy as could be. You may be able to get at it from underneath with the convoluted under tray off, but removing the wiper cowl is the way to go. You'll need an O2 sensor socket, and since the A/F sensor has the stupid collar, will likely have to grind the socket down some in order to fit within the collar. Or you can buy the factory Toyota O2 socket for a ridiculous amount and skip the grind work.

    If the car is ready for spark plugs or EGR circuit tear down and cleaning, now's a good time with the cowl off...

    Good luck.
     
    #5 m.wynn, Aug 27, 2017
    NutzAboutBolts and Raytheeagle like this.
  6. priusde

    priusde Junior Member

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    Thanks m.wynn. Will take a look at nutzaboutbolts spark plug replacement video to remove the wiper cowl.
     
    #6 priusde, Aug 27, 2017
    NutzAboutBolts and m.wynn like this.
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