Tim,

Sounds like a problem I recently had: I changed the majority of the
exhaust system before taking a long trip up to the UK and in the
process the O2 sensor wiring got wet (a mite careless with a drink in
the engine compartment.  The sensor itself was dry and I didn't think
anything of it.  On the first post-assembly drive at temperature -
loss of power, bucking, black smoke & hideous fuel consumption.
Switch off and back on gave another couple of minutes before symptoms
returned.  I thought the sensor had gone the way of the dodo, having
been 'disturbed' by the exhaust change so I disconnected it for the
trip until a couple of days ago, when I reconnected it out of
curiosity (and having discovered that a new VW one is DM200+ :(  ).
Now all runs OK with no problems.  Maybe it was wet wiring, although
I cannot detect any chafing or broken insulation.

The emisions check is due in a few days, so I should know soon if
the sensor is really u/s or not.  I'll let you know.

Regards,
Rich Lumb

>Tue, 14 Apr 1998 15:50:26 -0300
> Folks....
>
> Anyone have a problem with the 2.1l engine suddenly going super rich after a
> good dunking? Diesel black smoke cloud visible...........