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Thread: Idle Craziness going on

  1. #1
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    Idle Craziness going on

    I turned on my closed loop O2 feedback for the first time in a long time. As I stopped in the garage I glanced at the wideband gauge and I noticed it get really rich, then a bit lean, then back to normal. I've got a plot of what happened. Can someone explain what is going on here? The fact that the EQ command goes to 0.885, then up to 1.089, then back to 1.0 is really weird. All of this at idle. Any insight would be helpful. Thanks. This is on a 2012 Corvette LS3 with a Vortech supercharger. Both narrow bands are installed and a wideband.
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  2. #2
    Tuning Addict blindsquirrel's Avatar
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    Tune file.

  3. #3
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    That sounds like a cat test being run

  4. #4
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    Quote Originally Posted by blindsquirrel View Post
    Tune file.

    Here's the tune file.
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  5. #5
    Tuning Addict blindsquirrel's Avatar
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    Yep.

    screenshot.07-08-2022 16.29.56.png

    If it has no cats that needs to be off. Guessing they're gone since the downstream O2s are also turned off.

    In case you're stuck with one of the later software versions where that option's been removed:

    22_08_01_2Bar_6_O2FB_enabled - CT disabled.hpt

  6. #6
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    Quote Originally Posted by blindsquirrel View Post
    Yep.

    screenshot.07-08-2022 16.29.56.png

    If it has no cats that needs to be off. Guessing they're gone since the downstream O2s are also turned off.

    In case you're stuck with one of the later software versions where that option's been removed:

    22_08_01_2Bar_6_O2FB_enabled - CT disabled.hpt
    Sorry to hijack but I got a question for you blind. Should my e38 from 2015 camaro z28 have that cat test table in it? Im not seeing it in there under that tab. care to take a peek?daily tune vve.hpt

  7. #7
    Tuning Addict blindsquirrel's Avatar
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    Your file does have it... it's just been removed in Editor versions newer than 4.8.7.

    daily tune vve - CT disabled.hpt

  8. #8
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    Quote Originally Posted by blindsquirrel View Post
    Yep.

    screenshot.07-08-2022 16.29.56.png

    If it has no cats that needs to be off. Guessing they're gone since the downstream O2s are also turned off.

    In case you're stuck with one of the later software versions where that option's been removed:

    22_08_01_2Bar_6_O2FB_enabled - CT disabled.hpt

    Ok, that makes sense. It is good to know that this is a normal thing and not my car flipping out. When you say the downstream O2s are turned off are you referring to the DTC's or something else?

  9. #9
    Tuning Addict blindsquirrel's Avatar
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    Yes, the DTCs.

    I think why this comes up so often is, with no cats, and no downstream sensors, and the cat test enabled, it tries to run the test on every single run cycle because without the rear O2s it gets no result and so keeps trying over and over. With working cats and working O2s, it runs the test, sees it pass, and then only rechecks fairly infrequently. And usually not at idle.

  10. #10
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    Quote Originally Posted by blindsquirrel View Post
    Your file does have it... it's just been removed in Editor versions newer than 4.8.7.

    daily tune vve - CT disabled.hpt
    Thanks for the info Sir! Much appreciated.