I bought a costum softail it got S&S perfomanse muffler the only problem is when we go to Quebec province the cop check the muffler with a wire and if it go trought then they charge you I was wandering before I change the slip-on if there is something I can do to stop a wire to go throught??

 

You would have to modify the baffles. Cap the ends inside closest to the engine, but make larger holes on the sides. Should keep your sound, but might not be ideal for performance.