I am hearing that some Vanagons run at least as well or better with the O2
sensor unhooked.  This lends some credence to the one email I saw that
claimed the O2 sensor was there to prevent the cat from burning up in case
of serious FI problems.  My experience would back this up.  When I was
having problems with my '85 Digijet, the engine would go into what seemed
like a default mode.  It would continue running, with just enough power to
get home.  The cat would be red hot.  After I sorted out the FI system, no
more red-hot cat and no more power problems.  I am going to run the O2
sensor wire up front to a voltmeter and see what is really going on with
this thing.

                                                        Jay