my exhaust is broke. the pipe going into the muffler is no longer welded to the muffler. it just bounces inside. i am wanting to put a flowmaster on it and i dont know what to get. how big is my exhaust pipe? do i get the center in, center out, offset? i want a 40 series but i dont know about the in/out size. so if someone could help me out, i would appreciate it. i wanna buy one then take it to a shop and say put it on. Thanks in advance.