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Heated oxygen sensor wiring

Discussion in 'Gen 2 Prius Technical Discussion' started by anthonylokrn, Mar 13, 2013.

  1. anthonylokrn

    anthonylokrn Member

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    Does anybody what color is the signal cable on the heated oxygen sensor post-cat? Believe it is B1S2.

    I looked up some info but couldn't figure out exactly. Per the diagram, there is four cables- 2 HT, 1 +B, and 1 E.

    Thanks!
     
    #1 anthonylokrn, Mar 13, 2013
  2. anthonylokrn

    anthonylokrn Member

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    Just accessed the floorboard to look at the wiring. There are 2 black wires, 1 blue, and 1 white.
     
    #2 anthonylokrn, Mar 13, 2013
  3. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I don't know the color coding, but you might consider inserting a pin into a wire, then connecting a voltmeter from the pin to ground, to figure out what voltage is on the wire. That might help you to decide what wire does what.
     
    #3 Patrick Wong, Mar 13, 2013
  4. anthonylokrn

    anthonylokrn Member

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    Ok the blue wire is the signal wire.

    Soldered a 1.2k ohm 1/2w resistor inline to hopefully take care of the P0420 CEL. Driven 8 miles so far...hasn't came back up yet *cross fingers*.
     
    #4 anthonylokrn, Mar 13, 2013
  5. anthonylokrn

    anthonylokrn Member

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    Well the P0420 CEL still came back on even after soldering in a 1.2k ohm 1/2w resistor :(

    Any suggestions?
     
    #5 anthonylokrn, Mar 15, 2013
  6. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I assume that you would not like a suggestion to replace the catalytic converter?

    If so, then I suggest you remove the resistor since that won't help, and instead replace the upstream A/F ratio sensor with the correct Toyota part. If that sensor is highly responsive, the engine ECU may decide that the catalytic converter performance is adequate.
     
    #6 Patrick Wong, Mar 15, 2013
  7. anthonylokrn

    anthonylokrn Member

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    I've thought about it but wasn't really looking to spending $300 on a car with 160k on the odo already.
     
    #7 anthonylokrn, Mar 17, 2013
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