i have a 4 wire narrow band lambda sensor.

it has

1 grey wire
1 black wire
2 white wires

anyone know what wire is waht ?

im pretty sure the white are for the heater

but are both positive negative or. ????

 

white ones are the heater wires mate. yep.

If its a Ford Lambda probe, then the grey wire is the Sender wire
(the one for the guage you are hooking up i guess?)

BUT on after market sensors, sometimes the black wire is the
sender wire.. the instructions usually say on the aftermarket ones,
as they are universal..

 

whites are definitely the heater
Bosch sensors (and Ford zetec sensors that I have seen for that matter) are positive signal on the black, and grey is ground side of signal.