anybody notice black carbon build up on the front and rear of their stock mufflers rolled outside edge seams? I notice it even drips water on start UPS. I think the stocker is on it's way out. I will upload pics when I get a chance.
I was wondering the same thing. I haven't noticed black soot, but I have noticed water does drip from the rear at the bottom. I guess it's possible that this is normal, to prevent a build up inside.
pic: there looks to be a hole, but not sure and I am working and didn't have a flashlight, nor did i want to get underneath and get all dirty. The front has the same amount of buildup. Maybe this is a good reason to upgrade!
I have the same problem (minus black soot) w/ my muffler with no traces or sounds of exhaust leaks.. Soot might be a good indicator of a hole, try listen for exhaust leaks