I bought a 18'' magnaflow muffler from advance auto on line and shipped for $112.00, installed for $80.00 at a local muffler shop which included about a foot of 3'' stainless pipe for a factory fit. This seemed like a great deal to me. I thought about changing out the stock y pipe for a less restricted one but didn't. I really don't want to modify to much for fear of any hassle with the warranty. With the muffler its clamped on like the stock muffler was, easy to replace the stock back if ever need be.