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1998 toyota forerunner oxygen sensor wiring problem

Appx 6 " from the sensor, there is a 2-part plug connecting it to the wiring harness...somehow, the wires were pulled out of the plug, & i do not know the correct way to reattach them, since the color sceme differ differs..

from the sensor itself, the wires are a)blue, b)white, c)black, and d)black..
to the harness, the wires are A)red/white, B)white/blue, C)red, & D)brown...

i do not want to burn out my car's computer trying to find which wires
go where, & the harness display i show does not show this plug, at all..
i cannot take my smog test until this connection is made, so this info would be greatly appreciated at this time..

ie. a>B b>A c>D & d>C thank you bruce

please help me, only, if you know for certain...

Posted by bruce731 on

  • edwardzesty Dec 13, 2008

    I have a 2000 2wd. same problem. my catalytic converter was ripped out by scrap metal theives and they cut the electrical connector out. I have a call into a local dealership parts manager and was only offered a price on a new wiring harness to the engine plus labor. this adds up to thousands. he told me that the toyota manual does not show which color goes to which. this is crazy i'm thinking. i'm going to call another dealership to test this statement. There are 24 possible wiring configurations. what are the wire sizes on yours? Mine are #10, #18, #16, and #16, I think.



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Clck here for the correct wire colors for Toyota.

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go to any auto parts store and ask for a 12 volt test light, it has a bulb inside and a pointed end like an ice pick, u attach one end to a good ground and then probe wires for power, when u have a hot wire with 12 volts the light in the handle will shine on. They cost about $6.00 at Kragen I think.

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SOURCE: I have a reese brakeman compact trailer brake,

the best thing to do is get a 12 volt lite tester the one with the pointie end. cut your harness turn on left turn signel. with tester lite grounded tuch the ends of the cut wire from truck strip a small piece of wire covering and attach to your trailor harness when left signal works on the trailor do the right blinker the same way as for running lites turn on your park lites and see witch two wires are lit connect to trailor making shure lites are dim last wire are for brake lites now you well know where to connect to new harness good luck cj

Posted on May 21, 2010


Duane Wong

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What codes are you getting?

Posted on Dec 18, 2010

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What code mean po302,,,,po135...p1705

P0302 TOYOTA - Cylinder 2 Misfire Detectedxicon.jpg CodePossible causes- Faulty spark plug 2
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How do you change oxygen sensors on a 2000 hyundai sonata

Locate the two oxygen sensors on either side of the Sonata's catalytic converter on the exhaust manifold. The Sonata's oxygen sensor is gold and shaped liked a spark plug.

  • 2 Remove the Sonata's wiring harness from the end of the two oxygen sensors using your fingers. Do not damage the end of Sonata's wiring harness.
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    Welcome to

    The upstream oxygen sensor is typically found on the exhaust manifold that is bolted to the engine block. It may be as far up on the exhaust as the the manifold piping located in the front of the engine under the hood. The sensor looks like a plug sticking out of the exhaust piping and will be the only plug inserted into the exhaust system.


    Removal of the oxygen sensor is easier when the engine temperature is above 48CC


    ' Handle the oxygen sensors carefully in order to prevent damage to the component.

    Keep the electrical connector and the louvered end free of contaminants. Do not use

    cleaning solvents on the sensor. Do not drop or mishandle the sensor.


    Numbers in ten in parenthesis correspond to numbered components in image.

    1. Raise and support the vehicle.

    2. Disconnect the sensor harness connector.

    3. Remove the oxygen sensor.

    Bank 1 Sensor 2(1)

    Bank 1 Sensor 1(2)

    A Bank2Sensorl(3)

    A Bank2Sensor2(4)


    Important: A special anti-seize compound is used on the oxygen sensot threads. The new

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    1. Install the oxygen sensor.

    Bank 1 Sensor 2(1)

    A Bank sensor (2)

    A Bank2Sensorl (3)

    A Bank2Sensor2 (4)

    Important: Make sure that all of the harness retaining clips are intact. The harness

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    connecting the sensor pigtail to the harness, ensure that the connector seal is

    crushed uniformly all the way around between the connectors.

    2. Connect the sensor harness connector.

    3. Lower the vehicle


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