I had my OEM muffler replaced under warranty back in 2011 and now with my vehicle just out of the warranty period, I find myself with the same muffler buzzing sounds that we all know about... Just wondering if anyone else has had to replace there replacement OEM mufflers like I will be doing shortly... Call me crazy but I have never replaced a muffler on any other car before. My Yukon has 360k on it and the exhaust system is still good....

 

The people getting their mufflers replaced for the startup sound are kind of silly. I didn't think so at first, but we are basically junking a huge piece of metal for a sound that goes away in like 20 seconds.

 

I never had sounds at start up. I always had harsh metalic buzzing under acceleration.

 

Make sure it isn't some other item that just seems to go away when they replace the muffler.

 

I had mine replaced in 2011 for the startup sound, and then the warranty replacement sounded like **** during acceleration once the car warmed up. It sounded like making rapid farting sounds underwater. I had that replaced again and it sounded the same.

I took it off and put the optional sport exhaust on it and the problem went away. When I took it off, the thing was full of water. I talked to the service manager about this and the part supplier for the muffler changed like 3-4 times since 2008. It's possible there is a defect in the later muffler revisions that make it sound like ****, but since the muffler "works," they wouldn't do any more replacements.

 

My 13' had the diesel sound at startup for a few weeks, but the muffler must be getting settled in now as I do not notice it as much. In addition, there is a slight rasp sometimes under hard acceleration. My thinking is that in time these noises will balance out and a replacement is not needed.

 

I love my IPL exhaust system.

 

Only had to replace mine once. Replaced it with a Motodyne E370

FWIW, my car had no rattle before I took the exhaust system off, but I replaced the stock exhaust 2 days after I bought the car.

 

Had mine replaced twice. Same sound you are describing like a buzzing under acceleration.