weird that you have a leak at your oxygen sensor ..
though if you haven't checked it out really yet, speculating is not that
useful right now.

if it is cracked ..
it's not hard to have an exhaust shop weld in a new oxygen sensor bung..
it's a standard exhaust shop repair.

in case anyone is not aware.,...it is a standard rule to never allow any
silicone type sealants anywhere near an oxygen sensor, or where it can get
to the 02 sensor from upstream.

you'll see some sealants say 'sensor safe' on them.
if using any sealant in an exhaust system, which really isn't 'normal'
....be sure it's 02 sensor safe.

Scott
www.turbovans.com

----- Original Message -----
From: "William Greenamyer" <wgreenamyer@CISO.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Friday, September 24, 2010 7:20 PM
Subject: Re: Vanagon exhaust gaskets for 84GL Vanagon

>3 years is what I figured.  Now I know.  Only had two go bad.  Got all of
> the flanges as flat and matched and non-leaking the last time.  Guess it
> is
> just the fiber quality or something that allowed the #1 and #3 pipe
> gaskets
> to the head to start leaking air.  My shim to the Y-pipe worked perfectly.
> No leaks.  Have to see how I installed it last time.  Have to see which
> gaskets I used sealant on.  If all of the sealant gaskets held, then I
> will
> use the sealant throughout.
>
> Any ideas on what to do for the leak coming from the threads on the O2
> sensor?  I will more know more about how it is leaking when I get things
> apart.  Right now I am guessing a crack.
>
> William