Ernst has a perforated pipe sealed at one end. A failing cat will deposit its internals inside the muffler partially blocking exhaust flow. 

Chris

Dnia 02.07.2017 o godz. 20:55 Neil N <musomuso@GMAIL.COM> napisał(a):

> 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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