I was getting a P0432 and ended up having to replace the driver's side primary cat. My car has roughly 117k miles and is a 2004 which makes those cats 20 years old. I'm attaching a picture of the cat which had to be replaced and I'm concerned that there are metal pieces trapped inside the exhaust now.

2003 S55 still working at 80k miles

I've got almost 120k on my car so I went ahead and had an x-pipe put in their place. No noticeable sound difference but I was concerned about the heat building up in the exhaust.

At WOT is probably where you’ll hear and feel the difference. Please report back.

My ‘06 has 160k+ on the original cats.

maw

it's more mileage depending
and these should be good for A LOT
we nearly never seen a replacement on S class

I didn't notice anything.

I was really concerned about the heat as I live in Phoenix and also about the piece that blew out of the primary cat on bank two. I've combed through a lot of threads and have seen statements that these cars would still pass a sniffer test with just the primaries so I don't really feel any guilt about it.