Here the question: What would cause a Cat converter to break up inside? This is my 3rd one in three weeks.... The original was replaced last summer after my MSD ignition shorted causing a terminal meltdown it lasted until July when I got a banging sound inside. I drove it for awhile then I started losing power and engine temp started going through the roof. When the cat was removed it was replaced under warrenty, because it was al broken up and many of the pieces were gone. This was while using a stainless muffler from Aerospeed. One of the baffles in said "muffler" was loose and there was concern that possibly reversion was occuring causing the catalist to break up. That cat lasted 4 days in which I drove under 200 miles. So, in frustration a pipe was welded in while I waited for a new muffler. I got a nice ANSA muffler AMG style then ran all new pipe w/ a high flow
Catco cat. I have traveled 1560 miles since last Thursday(the day I picked it up), and it is already banging away. Is there a solution? Is it somthing simple? The catilist has not been melted on any of the removals.

P.S. this is on a 190E 2.3 16v if it makes a difference.