On my 6cyl 4x4 ‘05 model I removed my factory exhaust. I installed new JBA headers with 2 1/2 inch exhaust flanges. I built a 2 1/2 inch Y-pipe that follows the same route as the factory. From there I switched to 3 inch and ran into a three chambered Flowmaster. This proved to be too loud so I tried a large bodied Gibson muffler and that didn’t work for me either so I tried a large bodied SUV style muffler with all the fiberglass packing and it is also chambered. The volume is kind of what I’m looking for but around 3000 RPMs it produces a horrible metallic raspy sound, to me it sounds like one of those hot rodders in there no performance four-cylinder Civics. Has anyone deleted their cats, put on some headers and have any clue what I’m talking about? If so what was your fix? thank you.