16.679 Volt spikes coming from O2 Sensor

Discussion in 'General Tech' started by ForeverDriven, Jan 22, 2020.

  1. ForeverDriven

    ForeverDriven New Member

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    Title says it all. The 97 GT I just bought a while back recently threw a rich code when driving, then developed a pulsing/surging in 5th gear at the same time. No matter if I clear the code, the pulsing/surging in 5th is always there, and idle randomly gets really rough. Code is p0175.

    Here's the real problem though, I had just replaced another 02 sensor that was spiking as well, but this sensor was spiking within what you'd consider possible for a 14 volt system (lower than/around 14 volts).

    The shop said the sensors looked OEM, so I'm going to replace all the others and run it for a couple weeks while constantly clearing codes.

    Any thoughts or previous experiences would be awesome!

    Thanks,
    Blake
     
  2. 01yellercobra

    01yellercobra Active Member

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    I'd start by switching the sensors side to side. See if the code follows the sensor or stays on the one side. My guess is you're going to be chasing wires for shorts or something.
     
  3. 07GtS197

    07GtS197 Well-Known Member

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    In addition I would check the alternator. I’d say its probably on its way out.


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  4. ForeverDriven

    ForeverDriven New Member

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    Alternators near brand new!
     
  5. 07GtS197

    07GtS197 Well-Known Member

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    That doesn’t mean its not bad. Alternators for these cars are hit or miss, I personally have had a remanufactured one not work within a week of installing it. 16 volts doesn’t come from nowhere, its coming from the alternator.


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  6. ForeverDriven

    ForeverDriven New Member

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    Gotcha. If I got it tested would it show this type of problem?