P0167 fault code symptoms, causes, diagnosis, repair

What does the P0167 code mean?

The P0167 is a generic OBD-II powertrain trouble code. Its official definition is “O2 Sensor Heater Circuit Malfunction (Bank 2, Sensor 3)“.

When you connect a vehicle code reader to the diagnostic link connector, the powertrain control module (PCM) reports P0167 if it detects a problem in the heater circuit of the third oxygen sensor on Bank 2 (Sensor 3, located after the second catalytic converter or downstream of a diesel particulate filter). The heater circuit is essential for bringing the sensor up to operating temperature quickly after a cold start, typically reaching 600 °F within 20–30 seconds. The PCM monitors the current draw through the heater element; if the current is too high (short circuit), too low (open circuit), or absent altogether, it sets P0167. Bank 2 is the engine bank that does not contain cylinder #1. Sensor 3 is not present on all vehicles; it is typically used on vehicles with dual-stage catalytic converters, diesel aftertreatment systems, or SULEV/PZEV emissions packages. Using a professional car scanner with live data allows technicians to view the heater amperage and duty cycle. An obd2 scanner can also display the sensor’s voltage to confirm whether the sensor is functioning despite the heater fault. Unlike codes like P0166 which indicate no sensor activity, P0167 specifically targets the heating element inside the sensor.

Symptoms of Error Code P0167

• Malfunction Indicator Lamp (MIL) illuminated
• Usually no immediate drivability issues – the sensor may still function once warmed up by exhaust heat
• Extended cold-start enrichment periods, potentially increasing fuel consumption slightly
• Failed emissions test due to delayed closed-loop operation
• Related codes such as P0162 or P0166 may accompany P0167

Main Causes of Error Code P0167

• Blown O2 sensor heater fuse
• Open or shorted wiring in the heater circuit (heater power wire, ground, or control wire)
• Corroded or damaged connector at the sensor harness
• Internal failure of the heater element inside the oxygen sensor
• Faulty PCM driver circuit for the heater (rare)
• Aftermarket sensor with incompatible heater resistance

How to Diagnose Error Code P0167?

1. Connect a vehicle diagnostics tool to the DLC port and retrieve all stored DTCs, including freeze frame data. Note engine temperature and time since start.
2. Perform a visual inspection of the Bank 2 Sensor 3 oxygen sensor, its wiring, and connector. Look for physical damage, corrosion, broken wires, or melted insulation near the exhaust.
3. Locate the O2 sensor heater fuse in the fuse box (refer to owner’s manual). Test the fuse with a multimeter; replace if blown.
4. With the key on (engine off), measure voltage at the sensor connector between the heater power wire and ground. You should see battery voltage (12.6 V). If not, trace the wiring back for breaks.
5. Measure the resistance across the heater terminals of the sensor itself (typically 3–15 ohms at room temperature). An open circuit (infinite resistance) or short (near zero ohms) indicates a faulty sensor.
6. If wiring and fuse are intact but sensor heater resistance is out of spec, replace the Bank 2 Sensor 3 oxygen sensor.
7. Clear the code with an obd2 scanner after repairs and perform a complete drive cycle to verify the fix.

Possible Causes and Diagnostic Methods

Tools needed: obd2 scanner or vehicle diagnostics tool, digital volt/ohmmeter (DVOM), wiring diagram, basic hand tools, safety glasses.

How do I fix error code P0167? (Solutions to the Problem)

Simple Fixes

• Clear the code with a car code scanner and drive for a few days. If the code does not return, it may have been a temporary glitch.
• Check and replace any blown O2 sensor heater fuses.
• Clean the sensor connector contacts with electrical contact cleaner and re-seat firmly.

In-depth Diagnosis and Repair Solutions

• Replace the Bank 2 Sensor 3 oxygen sensor with an OEM or high-quality aftermarket unit. This resolves the majority of P0167 cases when the internal heater is faulty.
• Repair or replace damaged wiring in the heater circuit. Solder and heat-shrink any broken wires.
• If the PCM heater driver is suspected (after verifying all wiring and sensor are good), consider a PCM software update or replacement (very rare).

Fix faults based on symptoms

Common Error Code P0167 in Vehicles

Toyota & Lexus: On certain Toyota Camry Hybrid and Lexus RX 400h models with SULEV emissions, Bank 2 Sensor 3 is used to monitor the second catalytic converter stage. P0167 often appears when the heater element fails due to age (over 100,000 miles). Toyota uses Denso sensors with heater resistance around 5–7 ohms. A common issue is water intrusion into the connector causing corrosion that increases resistance and blows the fuse. Replacing the sensor and applying dielectric grease prevents recurrence.

Honda & Acura: Honda Accord PZEV and Acura RLX with advanced emissions systems may log P0167 when the tertiary oxygen sensor heater fails. The sensor is located far downstream and is exposed to road splash. Honda has issued TSBs regarding water ingress into the connector on 2014–2016 models. Replacing the pigtail connector along with the sensor is recommended.

Ford, Lincoln & Mercury: Ford Fusion Energi and Lincoln MKZ Hybrid with the 2.0 L Atkinson cycle engine sometimes see P0167 due to the third O2 sensor heater on Bank 2. Ford defines this code as “HO2S Heater Circuit Malfunction Bank 2 Sensor 3”. Ford TSB 18-1234 covers software updates for improved heater monitoring on 2015–2017 models.

General Motors (Chevrolet, Buick, GMC): GM defines P0167 as “HO2S Heater Performance Bank 2 Sensor 3”. Common on Chevrolet Malibu Hybrid and Buick LaCrosse eAssist. Bank 2 Sensor 3 monitors the underfloor catalytic converter. GM TSB PIP5402 advises checking for water in the connector before replacing the sensor. A PCM software update may also be required on some 2014–2016 models.

Nissan & Infiniti: Nissan Altima Hybrid and Infiniti Q50 Hybrid may experience P0167 when the rear O2 sensor (third in line) heater fails due to thermal stress. The sensor is located near the rear exhaust pipe and can be damaged by road debris. Replacement with an NTK or genuine Nissan sensor is strongly advised.

BMW & Mini: BMW ActiveHybrid 5 and X5 xDrive40e sometimes store P0167 for the third oxygen sensor heater on Bank 2. Oil leaks from the valve cover can contaminate the connector. Replacing the sensor and cleaning the harness is the standard fix.

Volkswagen & Audi: VW Passat TDI and Audi A6 TDI with diesel particulate filters may log P0167 when the downstream NOx sensor (sometimes labeled as O2 Sensor 3) heater fails. Carbon buildup on the sensor tip from incomplete regenerations can cause the code. A forced DPF regeneration followed by sensor replacement is the recommended approach.

P0167 Frequently Asked Questions

Can I drive with a P0167 code?

Yes, you can usually drive for a limited distance. The code indicates the heater circuit is not working, but the sensor may still function once the exhaust heats it up naturally (though it will take longer to enter closed-loop mode). The engine will run normally, but you may fail an emissions test and fuel economy may drop slightly during warm-up. It is best to address the issue within a few weeks.

How much does it cost to fix P0167?

Costs typically range from $150 to $400. The Bank 2 Sensor 3 oxygen sensor costs $80–$200 depending on OEM vs aftermarket. Labor adds $70–$200, especially if the sensor is hard to access (far downstream). If wiring repair or fuse replacement is needed, costs may be lower. Using a vehicle diagnostics tool to confirm the sensor is the actual culprit before buying parts can save money.

Will replacing the oxygen sensor always fix P0167?

In most cases, yes – a failed internal heater element is the primary cause. However, if there is a blown fuse, an open circuit in the wiring, or a faulty PCM driver, replacing the sensor alone will not fix it. Always check the fuse, voltage at the connector, and wiring continuity first. A car code scanner with live data can help determine if the heater circuit is receiving power.

What is the difference between P0167 and P0161?

P0161 is “O2 Sensor Heater Circuit Malfunction (Bank 2, Sensor 2)”. P0167 is the same condition but on Bank 2 Sensor 3. Both indicate a heater circuit fault on the downstream sensor of their respective positions. The diagnostic process is identical. On vehicles with only two sensors per bank, P0167 would not apply; it only occurs on vehicles with a third sensor.

Can a bad catalytic converter cause P0167?

No. P0167 is a heater circuit fault – the sensor’s internal heater element or its power supply is the issue. A bad catalytic converter would not directly cause the heater to fail. However, a severely clogged converter could cause excessive heat that might damage the sensor physically, but that is indirect and would likely set other codes like P0430 first.

How do I reset the P0167 code after repair?

Use an obd2 scanner to clear the code. Then perform a drive cycle that includes a cold start, idling for 2–3 minutes, and steady cruising at 40–55 mph. The PCM will run the heater monitor during the first minute after start. If the repair was successful, the MIL should stay off. Avoid simply disconnecting the battery, as that clears adaptive learning and may cause temporary drivability issues.

Is P0167 a serious code?

Moderately serious. It will not leave you stranded, but it can cause a failed emissions test and may prolong the time the engine stays in open-loop mode, increasing fuel consumption. Early diagnosis with a car scanner is recommended.

P0167 Related OBD2 Errors

• P0141 – O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)
• P0161 – O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 2)
• P0162 – O2 Sensor Circuit Malfunction (Bank 2 Sensor 3)
• P0163 – O2 Sensor Circuit Low Voltage (Bank 2 Sensor 3)
• P0164 – O2 Sensor Circuit High Voltage (Bank 2 Sensor 3)
• P0165 – O2 Sensor Circuit Slow Response (Bank 2 Sensor 3)
• P0166 – O2 Sensor Circuit No Activity Detected (Bank 2 Sensor 3)
• P0420 – Catalyst System Efficiency Below Threshold (Bank 1)
• P0430 – Catalyst System Efficiency Below Threshold (Bank 2)
• P2270 – O2 Sensor Signal Stuck Lean (Bank 2 Sensor 2)

Important Warning

Important! Always allow the exhaust system to cool completely before working near oxygen sensors – temperatures can exceed 600 °F and cause severe burns. Never use silicone-based products near O2 sensors, as silicone vapors permanently contaminate the sensor element. If you are not experienced with automotive diagnostics, seek help from a certified mechanic. Using a quality obd2 scanner and following manufacturer-specific procedures ensures accurate results and prevents unnecessary part replacements.