[wheelbender6]

Just thought of something that could help temporarily. Restrict your intake air a bit.
-Since high flow air intakes can cause a lean condition, seems that a more restrictive air intake could cause a richer mixture. I realize that restricting the intake kind of defeats the purpose of performance exhaust, but it may be worth it to prevent engine damage from a lean condition.
-Experiment by putting some electrical tape (or something that matches the color of your intake) over the intake opening to see if it helps. Start by adding just a bit of tape and add more, a little bit at the time to see if it helps the popping. Junkyard engineering works sometimes.
If the intake restriction doesn't help, it probably indicates that a lean mixture is not the problem.