P0167 code: O2 Sensor Heater Circuit Malfunction (Bank 2, Sensor 3)
P0167 means o2 Sensor Heater Circuit Malfunction (Bank 2, Sensor 3). The code says where to look, not what failed — the fix depends on which cause your car actually has.
What P0167 means
Every modern oxygen sensor has a built-in electric heater that brings it up to operating temperature within a minute or two of a cold start, long before the exhaust alone could. P0167 means the heater circuit for the bank 2, sensor 3 position — the sensor after the second catalytic converter, fitted only on some vehicles — has failed its electrical checks: the computer sees too much current, too little, or none at all. The most common cause is the heater element inside the sensor burning out, which means replacing the sensor since the heater is not serviceable separately. A blown fuse, a failed heater relay or driver, and wiring faults round out the list. Until it is fixed, the sensor warms slowly or not at all, so this code frequently drags a no-activity code like P0166 along with it.
P0167 symptoms
- Check-engine light, often soon after a cold start
- No drivability symptoms
- Catalyst or O2 monitors failing to complete
- Sometimes paired with P0166 (no activity from the same sensor)
What it costs to fix P0167
Typical range: $80–$450 · about ~0.2–1.5 hrs of labor
| If the cause is… | Part | Labor |
|---|---|---|
| O2 sensor replacement (heater is built in) | $30–$200 | ~0.3–1 hrs |
| Fuse or relay | $5–$40 | ~0.2–0.5 hrs |
| Wiring repair (heater power or ground) | $5–$60 | ~0.5–1.5 hrs |
A fuse-first diagnosis costs minutes and can save a sensor purchase — heater circuits often share a fuse with other sensors, so multiple heater codes at once strongly suggest a fuse or relay rather than several sensors dying together.
The price swings on which cause it turns out to be — so confirm the cause before paying. Diagnose P0167 for my exact vehicle →
How to fix P0167
Moderate — doable at home with common tools and patience
- Start at the fuse box: heater fuse and relay
Check the heater fuse first, and if your vehicle feeds the heaters through a relay, check that too. A dead fuse or relay leaves the Bank 2 Sensor 3 heater with no power and, because the sensor then stays cold, often brings P0166 along with it.
- Swap the relay with an identical one
Where the heater relay is a plug-in part with an exact twin elsewhere in the fuse box, swap the two and clear the code. If P0167 stops and the other circuit starts misbehaving, the relay was the problem. Only swap relays with matching part numbers.
- Measure the element at the sensor connector
Unplug the sensor and read resistance across its heater pins with the exhaust cold. Open means the element has burned out; a value far from the service-manual figure means it's failing. Either way the heater can't be replaced separately, so the fix is a new sensor.
- Check the heater's power and ground paths
If the element is fine, back-probe the harness with the engine running: on most layouts the feed should carry battery voltage and the other side should be pulled to ground when the heater is commanded. A drop of more than a few tenths across either side, or a corroded shared ground splice, is a wiring fault to repair.
- Replace the sensor and confirm on a cold start
Fit a new Bank 2 Sensor 3, soaking the old one first — at the far end of the exhaust it's usually rusted in. Clear codes, drive from a cold start, and confirm both P0167 and any companion P0166 stay away.
DIY or shop? Fuse and relay checks need nothing beyond the owner's manual, and the resistance test and sensor swap are a reasonable DIY job for anyone with ramps and a multimeter. The parts that justify a shop are a wiring fault in the long power or ground run to the back of the car, a seized sensor in a corroded pipe, or a fault that survives a new sensor, fuse and relay — at that point the engine computer's heater driver needs a proper check.
Tools for the DIY steps: Fuse puller and spare fuses · Multimeter · Ramps or jack stands · O2 sensor socket · Penetrating oil
Not sure which step applies to your car? Get the likely cause for your exact vehicle before buying anything for P0167.
Start a case with P0167 and your car. Redline weighs these causes against what your car shows, and names the check that would settle it before you buy parts.
Can I drive with P0167?
Redline can’t determine from a symptom or code alone whether your car is safe to drive.
P0167: common questions
Why do oxygen sensors need heaters at all?
They only produce accurate readings when very hot. Exhaust heat alone would take a long time to warm a sensor this far downstream — if it ever fully does. The built-in heater gets it working within a minute or two of start-up, so emissions monitoring begins almost immediately.
Can I replace just the heater in the sensor?
No — the heater element is sealed inside the sensor body, so a burned-out heater means a new sensor. The good news is that if the fault is instead a fuse, relay, or wire, the sensor itself is usually still fine and the fix is cheap.
I have heater codes for more than one sensor. What does that suggest?
A shared cause. Multiple heater circuits often run through one fuse or relay, and it is far more likely that a single fuse blew than that several sensors failed simultaneously. Check the fuse and relay before pricing sensors.
Will P0167 affect fuel economy or performance?
Not measurably. This sensor monitors the second catalytic converter rather than steering the fuel mixture. The practical costs are the lit check-engine light, an inspection fail in OBD-tested areas, and suspended monitoring of that converter.
Related trouble codes
Don’t have a scanner yet? A ~$25 Bluetooth adapter reads codes like P0167 from your phone. See our guide to the best OBD2 Bluetooth adapters. Run a repair shop? See Redline for shops.
Generic OBD-II reference. Manufacturer-specific behavior varies. Confirm with a scan tool and, for safety-related codes, a professional inspection. Cost ranges are reference ranges, not quotes.
Seeing P0167 on your car?
Every problem becomes a Case. Tell Redline what the car is doing: it shows what the evidence supports, what’s still missing, and what to check next, before you approve a repair.
“Inner pad ~1 mm. Outer pad 3 mm.”
Next: check the slide pins move freely before buying parts.