Conduit is usually galvanized or zinc coated (or something like that)
so I doubt it would weld into the cat too well.

Removing, modifying, or disabling any emissions equipment is
definitely illegal... But I doubt the EPA is going to come knocking.

Cheers,

Jeff

iPhone email.

On Oct 14, 2008, at 3:59 PM, Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM
 > wrote:

> there are many vanagons running with hollow cats.
> That by itself does no harm.
> ( if chunks of cat material went downstream into the
> muffler..........that
> could cause problems of course )
>
> a factor to consider ............a hollow can for a cat doesn't flow
> as well
> as  a good cat, or a straight pipe in place of a cat.
> don't tell anyone I said this ............but a slick thing to do is
> weld a
> piece of straight pipe into a hollow cat.   Best flow, least
> restriction.
> There's on size of EMT electrical conduit that fits perfectly - just
> weld it
> inside at both ends.  I've never done this of course, just heard
> about it.
>
> re 'puffing' from a muffler - the most fun one I ever saw would
> expand out
> on the side as pressure built in it........then
> release..........looked like
> the thing was alive and breathing.
> it might be technically illegal to run without a cat, even if no
> emissions
> testing are required on your year van in your state.
> ----- Original Message -----
> From: "Jim Johnston" <inmytree1@GMAIL.COM>
> To: <vanagon@GERRY.VANAGON.COM>
> Sent: Tuesday, October 14, 2008 6:06 AM
> Subject: Running without a cat...?
>
>
>> Hello all,
>>
>> Vehicle:  91 GL with 163,000+, manual
>> Location: Wilmington, NC
>>
>> I'm trouble shooting a stumbling idle.  I think I've found my
>> problem. I
>> noticed the exhaust puffing and the muffler had some odd sounds
>> coming
>> from
>> the muffler itself.  So I pulled the cat and muffler.  I only
>> snapped two
>> of
>> the three bolts.  It turns out, my catalytic converter has nothing
>> left.
>> It's completely empty.  The previous owner had a S & S Exhaust
>> system put
>> on
>> a few months before my taking ownership 3+ years ago.  The cat has
>> big
>> dents
>> in it.  My theory is this: when the shop put on the new Header and
>> Muffler,
>> they cleaned out the Catalytic Converter.  In NC, vehicles older
>> than 1996
>> do not require emissions testing.
>>
>> I started her up, while a bit loud, no more puff puff puff....
>>
>> Would running with an hollowed out cat lead to the muffler breaking
>> down?
>>
>> Now I have to figure out if I have to buy a muffler from S & S or
>> does a
>> stock muffler bolt up to the system.
>>
>>
>> Jim
>> Wilmington, NC