Who is correct about identifying an Air/Fuel Sensor?

• A. Technician A is correct; you can identify by the number of wires
• B. Neither technician is correct
• C. Both Technicians A and B are correct
• D. Technician B is correct; you cannot identify by the number of wires

Answer: (D)

Identifying an air/fuel sensor by the number of wires isn’t reliable. Air/fuel sensing devices come in different designs—narrowband sensors that mainly indicate rich or lean conditions, and wideband sensors that provide a precise air/fuel ratio. The wire count varies with the design, the heater circuit, and the manufacturer, so the same wire count can appear on different sensor types. The correct way to identify the sensor is to use official service information, or read the part number or connector style stamped on the sensor and compare it to OEM specifications.

That’s why Technician B is correct: you can’t determine the sensor type or identity just by counting wires. Rely on part numbers, markings, or the vehicle’s documentation rather than wire count.