Are most people just cutting the flange off for the muffler pipe after the y and running true duals that way? I just bought a dual 2.5 in/out and am wondering two things. If it has an internal x over; do I need an x over before it? Also are most people just cutting the y off and running pipes to a muffler then your own thing from there? Just getting ideas as far as how I want to do the install or how most people are doing it.