hole in muffler?

[redwngr]

Those weep holes have cost the muffler companies a lot of money in lost sales. Without them the muffler quickly rots away from the inside out.

Maybe it was need for emission system warranties that led to the change to stainless that increased exhaust life.

[Clocked92]

The Borla mufflers on my 2006 Mustang don't have weep holes and they don't recommend drilling one. They do recommend drilling weep holes in the mufflers for newer mustangs though. I guess it all depends on the design.

[waumo1]

I learned to drill weep holes in mufflers back in the 70s. The duals on my Pontiacs rusted out in no time before I started drilling the weep holes in all the mufflers and resonators.

[Bcmking3]

This thread helped me as I recently installed a borla S Type cat back on my 15 All terrain and I was installing some running boards and notices black soot on the back of the muffler and I was like "wtf ! That's a 1000$ system" so searched the forum and you guys have my answer. So yes Borla does install these on their system still - it's at the back (toward the cab) just above the rolled edge.