Date:         Mon, 5 Aug 2002 17:50:10 -0500
Reply-To:     Larry Alofs <lalofs@ENTERACT.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Larry Alofs <lalofs@ENTERACT.COM>
Subject:      Re: Revisiting the Catalytic Converter...
Comments: To: Andrew.Yarnell@KIMLEY-HORN.COM
Content-Type: text/plain; charset=us-ascii

Andy Yarnell wrote:
>
> Recently my Catalytic converter melted, and after a lot of great advice, I took it off and gutted the cat. My 1987 Vanagon Wolfy runs fine now, but was wondering why the cat failed in the first place? The research I have done so far indicates that my OXS may be bad, what do you think? I do not want to kill my engine, it will go south on it's own soon enough (head gaskets).
>
> I do not have any hesitation, bucking, or back firing. My headers are cracked in places which allows exhaust to leak. I am planning on replacing the exhaust system some day, but probably later than sooner.
>
> Any advice would be appreciated.
>
> Thanks,
>
> Andy

You should fix the exhaust first.  The cracks may be allowing air to
enter the exhaust stream, strangely enough.  This makes the exhaust look
lean as sensed by your O2 sensor and the ECU thinks it should enrich the
mixture.  Too rich mixture overheats the CAT.

Larry A.