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Where to get 02 sensor for Catalytic Converter?

Discussion in 'Gen 2 Prius Main Forum' started by enginestarter, May 1, 2019.

  1. enginestarter

    enginestarter Junior Member

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    I was advised to get the Klarius make.
    I have a good price for the unit with fitting parts.

    But then I was recommended to get the 02 sensor as well.
    (I assume this is the lambda sensor?)
    Where do I get this from?
    Just the sensor seems super expensive.

    I can buy a cheap replacement, with fitting kit AND sensor for £110.
    But just the sensor on its own is coming up as £70+.
    (I've been recommended NOT to buy cheap replacements for fear of not passing MOT)

    ALSO... a supplier said the sensor may not be required.
    My neighbour who is a car dealer said he thought the sensor would be at the back, where the cutting didn't happen - so would be still there? (That was just his guess though.)

    Any thoughts?
    Any advice would be great.
    Thanks.
     
  2. TMR-JWAP

    TMR-JWAP Senior Member

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    There are 2 sensors on a Gen 2 Prius.

    The Air Fuel Ratio sensor (still an O2 sensor) is located on the exhaust manifold and most likely was not touched by the thief.

    The second O2 sensor is located at the bend between the two catalytic converters. It screws into a bung welded on the passenger side of the pipe. It's wires go through the floor board on the passenger side of the car where it connects to the car harness. If someone cut your exhaust out, they most likely clipped the wires and took that sensor with it. It would have been a very kind thief to actually unscrew the sensor and leave it dangling for you.

    The ecu compares the voltage value of the AF Ratio sensor with the value of the O2 sensor. If they are the same, then the catalytic converter is doing nothing. The bigger the difference in Voltage, the better the cat is working. Once that deltaV is below threshold, the 0420 code is triggered.
     
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  3. enginestarter

    enginestarter Junior Member

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    @TMR-JWAP thanks for the reply.
    So I am very confused now.
    I can't simply just get the catalytic converter, but also need to get 1 or 2 sensors?

    What are these sensors called?
    Can you give any links?

    I don't get why it's so complicated. :(
    There really should be a dummies guide somewhere.
    It's not rocket science. I've spent many hours now reading and educating myself slowly.
    I still have some way to learn it seems.

    Help with the needed sensors would be really great.
    Thanks.
     
  4. lexidium

    lexidium Active Member

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    When they take the cat, the sensor goes along with it. They cut the wires and leave them dangling.
    You can get an aftermarket one at a reasonable price and re-connect it.
    You can find a wiring chart by Googling because the colours will not be the same.
    I fitted one ( It was simple ) and connected the wires with a connection box. It runs great.
     
  5. enginestarter

    enginestarter Junior Member

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    @lexidium thanks for the reply
    What should I be searching for?
    02 sensor? Lambda sensor?
    Thanks.
     
  6. lexidium

    lexidium Active Member

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    Lambda sensor for 2008 1.5 Prius (or whatever it is)