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CEL Front o2 sensor

Discussion in 'General Tech and Maintenance' started by jamesA, Jun 3, 2009.

  1. jamesA

    jamesA Well known pissed off telephone guy VIP

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    I've been pondering this for a while. I had gotten a Bosch o2 sensor when I started throwing the code, but it oddly enough went away so I never installed it.

    When I put on my DC header, it came back and I installed a generic o2 sensor that I had to splice shit together, (couldn't find the Bosch one after the move to my 2nd apartment) well the code eventually came back so I said fuck it and I got another Bosch plug in o2 sensor, tightened it down reset my ecu and all was fine for like 3 months.

    Two years later my CEL will come on and off over 3 months time, what am I missing? I know its in, and I doubt it doesn't work, what else can I do so this damn CEL isn't always staring me in the face?

    It really makes no sense, because i still get the same gas mileage and the car runs just fine.
     
  2. TurboMirage

    TurboMirage YEEAAAHHH VIP

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    how did you connect the wires? solder and shrink tube?
     
  3. jamesA

    jamesA Well known pissed off telephone guy VIP

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    I used the stock plug off my original o2 and spliced them with the little black splicer box that came with the generic o2 sensor. The stock harness leading to the ECU is still intact for when I put in the non-generic o2 sensor. The wiring and harness is intact exactly as it was when it rolled off the assembly line.
     
  4. TurboMirage

    TurboMirage YEEAAAHHH VIP

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    ahh, i would replace that splicebox with some solder and shrink tubing if you can.
     
  5. jamesA

    jamesA Well known pissed off telephone guy VIP

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    I did. Its a stock harness o2 sensor thats in there right now. It was one that was made especially for 99-00 Si's, clipped right into the stock harness. Which is why I'm confused as to why I'm still getting a CEL. I wonder if its not getting the readings because there is a header on the car instead of the stock manifold.
     
  6. Briansol

    Briansol Admins Admin VIP

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    cat might be fubar
     
  7. TurboMirage

    TurboMirage YEEAAAHHH VIP

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    if the cat was bad wouldnt the 2nd 02 sensor be posting the problem?
     
  8. jamesA

    jamesA Well known pissed off telephone guy VIP

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    Its acting like its not getting readings from the front o2 which is before the cat, the rear o2 has never caused a CEL.
     
  9. DESPAIN

    DESPAIN yep....mmhhm.......yep...

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    Maybe you have your black wires crossed that is what happened to me. Switched the wires around and ta da!!
     
  10. jamesA

    jamesA Well known pissed off telephone guy VIP

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    Its a plug and play o2 sensor, there is nothing to switch without splicing...
     
  11. Briansol

    Briansol Admins Admin VIP

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    obd2 compares pre cat and post cat o2 readings.

    its possible that its clogged, and getting too hot, and throwing a code.
     
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