One wire just has an O2 Sensor, Grounded to the Body.. I've not seen a two wire sensor.. Three Wire have two heater wires and One O2 Sensor Grounded to the Body Four Wire have Two Heater Wires, and Two O2 Sensor Wires, and Nothing is Grounded to the Body.. I thought the 5 wire were the Wideband Sensors, with all the stuff and Electronics that comes with it.. Cj
|