Info needed on NTK EGO sensor

[Asko T Heikola]

Hi there!

I have NTK EGO 4-wire sensor from Opel Vectra (I believe it is called
Vauxhall Vectra in UK). It's quite new (-96), and has markings and part 
numbers from GM, Siemens and NTK. The colors of the wires are: Red, black,
yellow and white. I have a reason to believe that it is of a heated type,
since there is a marking 12V printed on it. The yellow wire is signal and
the black wire is signal ground (probably isolated ground -type). It seems
to work well with A/F-meter I've built (using LM3914), but I've been
having problems with the heating (?) wires. Does anybody know the wiring
diagram or place where I would get one?

Thanks in advance!

Asko Heikola