P0167
O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 3)
The ECU detects an electrical fault in the heater circuit of the third O2 sensor on bank 2. Heater current out of range — open or shorted heater, blown fuse, wiring fault.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: easy
Symptoms
- Check engine light on after several drive cycles
- Slightly increased fuel consumption during cold start
- Delayed entry into closed-loop fuel control
- Failed emissions inspection (lambda readiness)
Common causes
Ordered by how often each turns out to be the cause.
- Heater element openCommon
- Heater fuse blownPossible
Parts involved
- Oxygen Sensor B2s3
- Oxygen Sensor Heater Fuse
- Oxygen Sensor Heater Wiring
P0167 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.