The ran the y pipe right after the mufflers. I wanted to keep the stock mufflers because I pretty much just like the look of dual pipes and don't care much for a loud truck (hunting). I had true dual (no mufflers) on my 2007 and grew to hate it so I had them put the mufflers back on. It was annoyingly loud. With the setup I have now it is deeper and a little more throatier than normal but not super noticeable and not loud and annoying at all.