Fine, try and stump me on the only = combination that I didn't address. Well let me think about this....... Since = I have never seen a lambda sensor with only two wires, I'm going to make an = assumtion and guess that you mean " there are really three wires, but two of them = are white. Does polarity matter on these wires?". If that is the case, = the white wires are different ends of a coil of heater wire and none of my = cheat notes say anything about polarity of wire. Seriously, either = direction is fine for the heater. If by some chance I'm wrong, and there exists = a true two wire sensor, then I'm afraid that you will have to contact the vendor.