I installed a two brothers racing slip on exhaust a few months back. Within the first day it was backfiring so much I could barely get it home. Did some research and bought a tuner. (Dynojet power commander V) It did the job for a while but now it’s backfiring again. Randomly too. Last ride I went for 6 hours without a hiccup and then 2 or 3 all within a minute.

Any thoughts or ideas?