William,

The oxygenator in oxygenated fuel is alcohol (ethanol).  My cat is
original and still working fine after 200k and I have always used 87
octane regular gas.  The main cause of cat destruction is an over rich
condition, which will cause the cat to get too hot.  Along with an over
rich condition usually comes backfiring, which can literally blow up the
cat.

Take the van to someone with a three gas analyzer and check out the
mixture through a range of rpms.  I have no other ideas for you, maybe
someone else does.

"Greenamyer, William L" wrote:
>
> Nobody really answered this from my earlier post about the catalytic
> converter.  It does not specifically state what gas to use in the Vanagon.
> The manuals seem to act like I am supposed to know.  I have been using
> mostly ARCO regular (octane 87) and it seems to be doing fine except for the
> degrading converters but I don't know that the two are related.  I know that
> alcolol in the gas can be a problem.  What about oxygenated fuel?
>
> William Greenamyer
> California

--
Stuart MacMillan
Manager, Case Program
800-909-8244 ext 208

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