The problem is actually not that simple..
The R32 in RB20DT/DET & RB25DE form 08/93 to 01/95 use the same lambda as the R33 RB25DE, the original being NGK/NTK 205 OEM, Nissan part number 22690-73L11.
01/95 to 01/96> 22690 - 85TOO
The original Nissan part defies convention in that whilst it appears to be Titania due to the wire colour codes it is in fact Zirconium, wires are white, black & red.
There is however a way to identify the absolute item, as the Titania version has a 12mm fitting whilst the Zirconium has 18mm. Both have the same wiring and both have the same plug/socket fitment!
I have had serious discussions to day with both manufacturers and vendors, none of whom have a clue what they are talking about, or at least not the one's I spoke to. The manufacturers staff in the UK lack any knowledge whatsoever of products originating outside of the UK, and to a man declined to check with or put me in contact with overseas offices. Bosch for example absolutely stated they did not have a unit directly equivalent to the Nissan/NGK/NTK part quoted above, but I see folks selling it for the job, which I dare say it does after a fashion, but I don't run a Micra so it's not good enough until I see it proved good enough.
I do though have an NGK/NKT part on the way, which is said to be an acceptable equvalent and an upgrade..we will see.
I did learn some useful stuff though, thanks to some interesting links provided by manufacturers and one or two vendors. the fact that whilst universals etc may work and get you going, they do not provide optimum running. Apparently (scope graphs provided on the tech sites visited) O2 sensors don't just provide either 0.5 (Titania) or 1v, (Zirconium) they have a characteristic response curve deisgned for specific applications, so the wrong type will not provide totally accurate readings to the ECU.
As for the wires, without checking back and from what I remember (brainstorm time) 3 wire units provide the same functions, but possibly on different wires.
I'm away to read some more, again and agian and again and....
Aitch