3 upstream o2 connectors?!? (which ones to use)

Discussion in '96-04 - 2V Specific' started by brendancunningham, Dec 31, 2014.

  1. brendancunningham

    brendancunningham Member

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    I have three upstream o2 connectors.
    two that connect to the engine harness on the drivers side
    and 1 that is part of the tranny harness
    The engine harness is for a 98 gt(the MY of the car)
    and the tranny harness is from a 2002(?)

    I assume i use the ones that connect to the engine harness but I'm not sure as maybe there is only supposed to be one o2 sensor that connects to that harness( I'm using the old o2 harness from my v6
     
  2. D3VST8R96GT

    D3VST8R96GT Well-Known Member

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    Isn't the 6... 2 upstream and 1 down stream?
     
  3. MustangChris

    MustangChris Legend Retired Staff SN95 Supporter

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    there should be four.... two that connect to the transmission harness above the cross-over, and two that connect at the front (behind the intake manifold)

    from my experience, the 96-98 transmission (or engine) harness does not mate with the 99-04 engine (or transmission) harness. I had to buy both the engine harness AND the tranny harness for my swap.
     
  4. brendancunningham

    brendancunningham Member

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    2 upstream and 2 downstream
     
  5. brendancunningham

    brendancunningham Member

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    So you are saying that the 99-04 transmission harness won't work with the 96-98 engine harness? is it pinned differently or something?
     
  6. dino

    dino Active Member

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    Well, for one, 99-04 used an electronic speedo sensor and the previous used a mechanical.
     
  7. brendancunningham

    brendancunningham Member

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    I know that I have a speed cal to correct that problem I'm running a tr3650
     
  8. dino

    dino Active Member

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    What year car is it going in?

    Speedcal does nothing for a mechanical speedometer...
     
  9. brendancunningham

    brendancunningham Member

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    98