My original factory muffler on my 2003 2500HD started to rattle and the bottom sheet metal was caked up. I was looking for a "quiet" muffler and came across one that a lot of people have described as quiet. Spring. I was beyond disappointed when I lit it up after installing it and it was louder than the 16 year old muffler I just cut. Not thrilled, but it's already done, so I'll live with it. At least the rattling was gone, it was easy. I had a dual outlet on my old muffler so I had to make a cap to cover one of the exhaust pipes. The unused pipe was the one with the hanger, so it had to be left in to make installation easier.