The cat on my '88 260e has a bad internal rattle. Appearance-wise it looks very solid on the outside. I don't want to shell out the big $ for a new converter and thinking about either deforming the outside shell with a big clamp, or putting some screws through the outer shell to hold whatever is loose in there.

I believe there is a core element inside but is there also a case around the element? I was hoping if someone could describe what is inside it would help me with my plan.