most likely an extension or shortening, of the piece that connects to the cat. Any muffler shop should be able to do it. I considered doing the same thing myself and am still kinda on the fence about it. In my opinion the y pipe is kinda silly and two mufflers while prettier are also heavier. I could still be wrong as I've never seen a side by side comparison but I can't imagine the differences could be that great. Purchase at your own risk but my two cents say it should be easy to fab in.