C55 Catalytic Converters
I've included a couple of photos from a cat article I wrote. This first one has a gazillion miles, and it's partially clogged.

This second cat is new.

Your's looks a lot like the new one. It's been my experience that when MB cats go bad, it's because the welds that hold the ceramic substrate in place fail. The ceramic core then rattles around until it breaks up into small enough chunks to clog the cat itself, or the muffler. That's the secondary reason why cats with a metal substrate are so much better - the welds hold up. The primary reason is they flow better.

You have four cats ... that's way too many.
Seriously ... https://mbworld.org/forums/showthrea...170&highlight=
My cats collapsed & created a surprising amount of back pressure. The new cats are purrrrrrring like new.
Last edited by Brabus C55; Apr 19, 2008 at 01:26 AM. Reason: i cn't f'ing tyyype .... wwhyyyy ?!!/?1?1?

I was kind of bored!! I went thru the exhaust tips for the back-side of the secondary cats. I then went thru the O2 sensor to look at the front of the secondary cats and the back-side of the primary cats. I did not look at the front of the primary, which could be done thru the other O2 sensors.

Resonator Pic attached
Last edited by AMG DUDE; Apr 19, 2008 at 07:19 PM.
It's been my experience that when MB cats go bad, it's because the welds that hold the ceramic substrate in place fail. The ceramic core then rattles around until it breaks up into small enough chunks to clog the cat itself, or the muffler. That's the secondary reason why cats with a metal substrate are so much better - the welds hold up. The primary reason is they flow better.







