P0141: O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 2)
Key takeaways
- P0141 means the engine computer sees a fault in the heater circuit of the downstream oxygen sensor on bank 1, the one behind the catalytic converter.
- The engine runs the same, so it's safe to drive, but the car will fail an OBD emissions inspection until it's fixed.
- Check the O2 heater fuse ($0–$20) and the wiring near the exhaust ($100–$250) before buying a sensor.
- When the fuse and wiring are fine, a new downstream sensor at $150–$400 installed is the usual fix, because the heater is built into the sensor.
- Ford, Subaru and Fiat/Jeep have bulletins naming P0141, ranging from revised sensors to engine-computer software updates.
What P0141 means
The heater inside the oxygen sensor behind your catalytic converter isn’t working, or the computer can’t tell whether it is. The scanner name is O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 2). Oxygen sensors only read correctly when they’re hot, so each one has a small electric heater. The engine computer powers that heater and watches the current it draws, or how fast the sensor warms up. P0141 sets when the current is missing, too high or too low. Sensor 2 is the downstream sensor, after the converter. Bank 1 is the side of the engine with cylinder 1; on a 4-cylinder it’s the only bank.
Is it safe to drive?
Yes. The downstream sensor mostly checks the catalytic converter, so fueling and power don’t change. You’ll fail an OBD emissions inspection with the light on, and the converter monitor won’t finish until the heater works. What changes the answer: a rough engine, a fuel smell, or a flashing check engine light. Those point to a different problem that happens to share the light, and they need attention before the sensor does.
Causes, ranked
| Cause | How you confirm it | Typical cost (US independent shop, 2026) |
|---|---|---|
| Heater element in the sensor burned out | Heater resistance open or out of spec at the sensor side of the connector; fuse and power are good | $150–$400 |
| Blown O2 heater fuse | Fuse chart in the owner’s manual; no power at the sensor connector | $0–$20 |
| Wiring or connector damage (wires melted on the exhaust, corroded or loose plug) | Visual check under the car; power and ground at the connector with the key on | $100–$250 |
| Engine computer software (some makes) | A bulletin for your exact model and year names P0141 | $100–$200, often $0 under warranty |
| Heater driver in the engine computer | Power and ground at the sensor are good, sensor tests good, computer doesn’t switch the heater | Varies; rare |
A burned-out heater is the most common answer, and the heater is built into the sensor, so you replace the whole sensor. But the fuse and wiring are cheaper to check, so a good shop rules them out first.
What to check first
- Read all the codes. If heater codes for other sensors (like P0135) set at the same time, suspect a shared fuse or power feed rather than two bad sensors.
- Check the O2 heater fuse. If it’s blown, replace it once. If it blows again, there’s a short in the wiring or in a sensor heater. Find it before driving on.
- Inspect the harness. Follow the sensor wire from the exhaust pipe up to its connector. Look for wires resting on the pipe, a broken clip, or green corrosion in the plug.
- Measure the heater. A shop checks heater resistance at the sensor and power at the connector. That tells sensor from wiring in a few minutes.
- Replace the sensor last. Then clear the code and drive; the heater test usually runs within the first few minutes after a cold start.
- Check bulletins. Ford names P0141 on the 2019–2020 Edge and Nautilus 2.0L and the 2018–2019 EcoSport 2.0L; Subaru offers revised oxygen sensors for 2020–2023 Outbacks; Fiat and Jeep bulletins are engine-computer software updates. On those models, ask about the bulletin before buying parts.
What it costs
The cheap outcome is a fuse, under $20. The common outcome is a new downstream sensor at $150–$400 installed, or a wiring repair at $100–$250 if a wire melted on the exhaust. It’s rare for this code to run past that. Checking the fuse and harness first costs little and catches the cases where a new sensor wouldn’t help. Our O2 sensor check engine light guide covers the rest of the sensor family.
Related codes
P0141 often shows up with P0138 or P0140 on the same sensor, because a cold sensor can’t read correctly. If P0420 follows, fix the heater first; the converter test depends on this sensor. If the car otherwise runs fine, ask our AI mechanic which code to chase first.
What owners report to NHTSA
11 complaints filed with NHTSA mention P0141, 6 of them since 2015, across 9 different models. The component owners most often filed it under: engine.
Manufacturer service bulletins that name P0141
70 technical service bulletins and manufacturer communications filed with NHTSA mention P0141, from 12 makes. A bulletin means the manufacturer has documented a known cause or a fix procedure for that model. Examples:
- SUBARU OUTBACK (2020, 2021, 2022, 2023), bulletin 11000828: This bulletin announces the availability of new oxygen sensors developed to address the following Diagnostic Trouble Codes (DTCs); P0137 (O2 Sensor Circuit Low Voltage Bank 1 Sensor 2, P0138 (O2 Sensor Circuit High Volta…
- FORD F-650 SD (2020), bulletin 10181940: Some 2020 F-Super Duty vehicles equipped with the 6.2L or 7.3L engine built on or before 05-Jun-2020 may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTCs) P0132, P0135, P0138, P…
- FORD F-250 SD (2020), bulletin 10199477: Some 2020 F-Super Duty vehicles equipped with a 6.2L or 7.3L engine, 10R140 transmission, and built on or before 05-Jun-2020 may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTCs…
- FORD EDGE (2019, 2020), bulletin 10202794: Some 2019-2020 Edge/Nautilus vehicles equipped with 2.0L EcoBoost engine and built on or before 14-Oct-2020 may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTCs) P0137, P0141 an…
- LINCOLN NAUTILUS (2019, 2020), bulletin 10202794: Some 2019-2020 Edge/Nautilus vehicles equipped with 2.0L EcoBoost engine and built on or before 14-Oct-2020 may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTCs) P0137, P0141 an…
- FIAT 500X (2016), bulletin 10198417: Flash: Powertrain Control Module (PCM) Updates This bulletin involves reprogramming the Powertrain Control Module (PCM) with the latest available software. Customers may experience a Malfunction Indicator Lamp (MIL) illu…
Sources: NHTSA Office of Defects Investigation complaint database and manufacturer communications file, snapshots September 2026. A complaint or bulletin that mentions a code is a report about that vehicle, not a statement that the code has one cause.
Frequently asked questions
What does the O2 sensor heater do?
An oxygen sensor only reads correctly when it's hot. The heater is a small element inside the sensor that brings it up to temperature within a minute or two of a cold start, so the computer can use it before the exhaust warms it.
Can I drive with P0141?
Yes. The downstream sensor mostly monitors the catalytic converter, so the engine runs normally. You'll fail an OBD emissions inspection, and the converter test won't run until the heater works.
Can I just replace the fuse?
You can, but a fuse that blew once usually blew for a reason: a wire rubbing on the exhaust, or a shorted heater in the sensor. If the new fuse blows again, find the short before trying a third.
How much does it cost to fix P0141?
Under $20 for a fuse, $100–$250 for a wiring repair, and $150–$400 for a new downstream sensor installed at an independent shop.
What's the difference between P0141 and P0135?
Both are heater circuit faults. P0135 is the upstream sensor (before the converter), and P0141 is the downstream sensor (after it). If both set together, suspect a shared fuse or power feed first.