----- Original Message -----
From: "Debra Clark" <clark10006@COX.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Sat 08 May 2004 08:22
Subject: Catalytic converter noise

> Just in the last couple of weeks, I've started to hear a sort of rattling
> noise from the rear.  It becomes faster and more pronounced as I step on
the
> gas.  Upon closer inspection, it seems to be coming from the catalytic
> converter which, I assume, is original equipment.  I have a 90 multivan
with
> about 148,000 miles and it was successfully smogged about a year ago so I
> have another year to go before another.  My questions are:  Is this noise
> typical for a failing cat?  Are they difficult to change out?  And if I
just
> live with it for now, will there be increasing noise or other
consequences?
> I did search the archives but these things weren't covered.
>
> Thanks, Debra

Debra,

As Bob said, check the O2 sensor first, if it's loose, tighten it!  If it is
the converter elements breaking up, as Robert said, it should be replaced as
soon as possible.

Now that I have repeated what others have said, here is my advice, as
someone who just had it replaced.  The cat is fairly easy to replace since
it is out in the open, the biggest issue is the (corroded) bolts holding it
in (penetrating spray is your friend).  On mine, it required the use of an
air chisel to remove the bolts, and ultimately a gas torch for one of the
bolts.  I would recommend having a replacement O2 sensor handy, as mine had
"become one" with the cat - removing it destroyed the threads on the sensor,
so I had to have it replaced.  When installing the O2 sensor, remember that
you must use "O2 sensor safe" anti-seize, as regular anti-seize will destroy
the sensor in short order.

Don in Phoenix, AZ
1987 Vanagon GL Syncro