I'm getting frustrated, I have a stupid vibration/ noise as exactly 95 km/hr or just below 60mph. I'm almost positive its my exhaust system because it started shortly after i installed it. I've had my buddy who is a gm tech check everything on the truck, u joints, driveshafts, shocks, belts, pulleys etc. We check clearances and etc for the exhaust but there dosen't seem to be anything wrong.The noise is when your under load at appropriately 2000rpm and 57 mph it can best be described as an air-hammer in a garbage can. It also vibrates like a mo fo, sounds like the trucks gonna explode sometimes and is worse when its warm from driving a while. Its so bad that you can feel the pedals buzzing under your feet with work boots on. I've emailed mbrp and they say that there maybe an issue but then never got back to me after that. If anyone has any other ideas or have heard anything similar let me know, i'm either gonna get a new muffler or get my money back just need some imput to make a good case to them. Oh yeah its a side exit mbrp catback system too, dont buy it .