Ok. I see. Thanks Stuart.

I'd seen first hand what a cat element might look like once it's done.
The one I saw looked like it had melted and shrunk but at that point
was more or less intact.  I don't recall my cat making any noise until
the "ball bearing" sound event which stopped after a short amount of
highway driving. I bet that element is all gone now.

There are times when my van has better acceleration. It could be the
87 octane gas I'm using but I'd wondered if maybe a chunk of the cat
wasn't intermittently clogging the exhaust.

Fortunately, for now, I'm technically ok w/o a cat; my bus didn't come
with one from the factory.

Neil.

On 7/2/17, Stuart MacMillan <stuartmacm@gmail.com> wrote:

> My experience with a couple of OEM cats is they slowly disintegrate. They
> are a ceramic honeycomb of small straight through holes.  Either they plug
> up from big pieces going sideways or the break into small chunks that are
> eventually pulverized in the muffler and blown out as expensive dust.  The
> cat in my '85 had about 1 1/2" of the core left and a golf ball size piece
> rattling around inside. Soon it would have emptied itself.
>
> Stuart
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
> Neil N
> Sent: Sunday, July 02, 2017 4:02 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: 2.1 Ernst Muffler Design and Failing Catalytic Converter

> When a cat element fails, do the pieces usually get blown out the tail
> pipe?

--
Neil n

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