That could well be true if it was a California model since those use the
ECU end for grounding the coax shield. But yours is a 49-state model,
according to the 15+ different inline 4 Digifant wiring diagrams I
checked before replying. And yes, the 92 Cabriolet non-Cali diagram
matches your wiring description for the O2 and almost nothing else does
but 90 and 91/92 Cabriolet non-Cali.

Even the single wire O2 VWs ground the coax shield, but at the ECU end
of the harness. Cabriolet non-Cali 90, 91, 92 models do it at the engine
side of the wiring.

Mark

Don Hanson wrote:
>    Well lots of confusion and I certainly appreciate all the answers.....  I
> called the guys at Van Cafe and asked them, since they sell a lot of the
> single wire O2 sensors..They ran out to the shop and asked their
> mechanic...he says people only need the signal wire...everything else that
> was connected for a 4 or 3 wire sensor is superfluous once you swap to the
> single wire one...............
>
>