quick o2 sensor questions

[jdm_master_X]

1.what are do the in-lead numbers mean on the o2 sensor? does it measure wire length or wire width, etc.?

2. can 3 wire o2 sensors be rigged to work on other cars if their from the same brand (meaning question#1 would somewhat be true?)

3. what qualifies an o2 sensor to be WIDEBAND? does it really have to be a 5 wire? (i found an article on the SR forum where one guy said it has to be 5 wires, but another guy in the same forum is using the 300zx TT OEM replacement from Bosch, which is also 3 wires right?)

stupid question, i know, but ive searched everywhere.

i have the part numbers for Denso 3-wire o2 sensors for the Nissan Sentra (SR20DE), Saab 900, BMW M3, and Nissan 300zx TT. thanks!

[jdm_master_X]

anybody? your help is greatly appreciated! please?