What it means
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.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Bank 2 Sensor 3 is the third oxygen sensor in the bank 2 exhaust path on vehicles equipped with one, and its heater helps it become active after startup. P0167 indicates an electrical malfunction in that sensor's heater circuit, which can delay warm-up and emissions monitoring.
Common causes
Most likely first.
- Heater element open
- Heater fuse blown
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)
How to diagnose it
- Read freeze-frame data and check live data to see when the Bank 2 Sensor 3 heater fault occurs.
- Inspect the sensor connector and heater wiring for corrosion, loose pins, chafing, or heat damage.
- Check the heater fuse and circuit power supply where applicable.
- Test the heater element, ground, and control wiring against the manufacturer's specification.
- If wiring and supply are good, confirm that the Bank 2 Sensor 3 heater has failed before replacing the sensor.
Common fixes
- Clean and secure the Bank 2 Sensor 3 heater connector.
- Repair damaged or shorted heater-circuit wiring.
- Replace a failed heater fuse after finding the cause.
- Replace Bank 2 Sensor 3 if its heater fails testing.
Can I keep driving?
The car is usually driveable, but the heater fault can delay emissions readiness and increase emissions during warm-up. Fix it before an emissions inspection, and avoid unnecessary short cold-start trips.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.