can anyone tell me what the 4 wires on a ford lamda sensor should be connected to.The wires are white,black,black with white trace ,green with yellow trace.

Chris

Ive not seen them colours before.

There are normally Two white a Gray and a Black.

The whites are the heating ellement and are not polarity sensative. One is a switched live and the eec ecu switches the earth.

The other two are the sensor.

Grey is the sensor earth and the black is to the ecu.

The wires change coloures at the connector.
So the the two white wires are not polarity sensative.does that mean i can use either white wire for switched live and earth?

Chris

Yes, those two just go to the heater element which doesn't care about polarity.