Combined with an exhaust pipe (mandatory), this is the easiest and cheapest way to replace a rotten muffler. It's nice and quiet. Installation Tips: When cutting a factory muffler, cut as close to the muffler body as possible as you need to preserve as much length of the factory front muffler pipes as possible. The factory front muffler pipes are slightly larger than the muffler inlet. Usually the intake pipe is inserted into the muffler inlet, but in my case (2003 6.0L) I used a pipe expanderโฆ