4 Wire Oxygen Sensor Wiring Diagram | Free Wiring Diagram Variety of 4 wire oxygen sensor wiring diagram. A wiring diagram is a streamlined standard pictorial depiction of an electrical circuit. It reveals the components of the circuit as streamlined forms, and also the power as well as signal links between the tools. Do I have to rely on wire color to correctly wire up an O2 Do I have to rely on wire color to correctly wire up an O2 sensor? Ask Question No, you don't have to rely on wire colors to figure out what's what. Browse other questions tagged electrical wiring o2-sensor or ask your own question. How to Wire a 4-Wire Universal Oxygen Sensor | It Still Runs This sensor measures the amount of unburned oxygen that is present in the oxygen as it exits the vehicle, which is indicative of the fuel mixture. The four-wire universal oxygen sensor must be changed approximately every 60,000 miles and requires a specific wiring process.