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Thread: Intermittent WBO2 drop back to heating.

  1. #1

    Default Intermittent WBO2 drop back to heating.

    Hi Guys. Just installed the Sniper XFlow onto a 383 Clevo with 3V heads and a decent cam, 540 HP at the flywheel. On the test drives, I occasionally get the WBO2 sensor dropping back to heating and it seems like it cuts fuel as the revs drop and car slows. I took a datalog. Anyone had or heard of this issue? The engine was running fine with a carb before this install and I've driven about 45 minutes with the Sniper. It seems I cannot upload the datalog file into here.
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    Last edited by Joels Garage Gear; 10-13-2019 at 05:02 PM.

  2. #2
    Join Date
    Oct 2016
    Albuquerque, NM


    You need to zip your datalog file (and attach it with your Config File). It's really hard to tell from such a tiny picture, but it looks like you might have EMI/RFI. Those spikes going all kinds of different directions are a key indicator. Do you have negative times on there as well? Do the usual with making sure any wires are not close to your coil or spark plug wires. Make sure you have all of the necessary grounds as well. These issues are well known and you can find a lot more detail searching for EMI/RFI.
    1968 Camaro, 383 with Dart Pro 1 aluminum heads and Comp Cams roller cam, Holley Sniper EFI with Dual Sync distributor, Muncie M21 4-speed transmission, 3.73 12-bolt Eaton posi differential.

  3. #3
    Join Date
    Nov 2014
    Ont. Canada


    Quote Originally Posted by bryaneh View Post
    It's really hard to tell from such a tiny picture, but it looks like you might have EMI/RFI.
    I agree with Bryaneh.

  4. #4


    You have a ton of EMI. I can barely see it in the picture, but I can see negative time and overlapping traces. That is the ECU resetting itself due to EMI.
    69 Camaro
    400 SBC, ProCharger D1SC

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