There is a small port on the J pipe, the last piece of exhaust before the
catalytic converter. I believe it's present to insert an exhaust gas sensor
for tuning purposes. That may be what you're seeing.

-Mark

On Tue, Nov 13, 2018 at 11:32 PM Dennis Haynes <d23haynes57@hotmail.com>
wrote:

> For the GoWesty exhaust the O2 sensor port should be in the Cat as it is
> with the 2.1L.
>
> Dennis
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
> Of Jeff Palmer
> Sent: Wednesday, November 14, 2018 12:06 AM
> To: vanagon@GERRY.VANAGON.COM
> Subject: GoWesty exhaust and oxygen sensors
>
> This summer i had the GoWesty stainless exhaust installed on my 85
> Westfalia (with a Boston Bob 2.1).  I noticed today that there doesn’t
> appear to be an oxygen sensor, and a smaller bolt is blocking it off. I
> remember the oxygen sensor as being closer in size to a spark plug. Is my
> memory failing me? Wondering if the GoWesty is a different size for some
> reason or if my mechanic didn’t bother to transfer the sensor over for some
> reason?
>
> Thanks
> Jeff
>
> Sent from my iPhone
>