Lambda details?

On my '90 760T does anyone know how many wires are on the lambda probe/o2 sensor? Any ideas on the colors of the wires too? Im asking as mine is flashing up as faulty and there are a number of 1-4 wire universal sensors for sale on Ebay. I want to make sure I buy the right one. Thanns in advance.

Its the code reader under the bonnet. I cant remember the exact sequence the light flashed in, its been a while since i read it, but it was decoded as faulty lambda/o2 sensor. BTW, I have found out that its a 3 wire sensor.

Lambda 

Suggest you give these folk a try.... Cheers Jack