What are the different names of wires on an O2 sensor?

Answer by  JBear (184)

The black wire is the power ground. The white wire is the key power. All O2 sensors will have one more wire which is the Hego signal. If there is a forth wire on the O2 sensor it is the signal return/ Hego ground. Hego is short for Heated Exaust Gas sensor.

Answer by  jimbo57 (17)

02 sensors, depending on their respective vehicle application, can have either two or four connection wires. two wires will be signal and ground and in the case of the four wire sensors the remaining two will be for the 02 heater.