P0141: O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)
The heater in the rear oxygen sensor on bank 1 has a fault.
Severity: 1 of 4
Generally safe to drive. Engine performance is usually unaffected. Repair before an emissions test.
Estimate range covers the repairs listed below; see the cost breakdown. A flashing check engine light, a hot temperature gauge, or brakes that feel different mean stop driving and get help.
What P0141 means
Same idea as P0135, but for the downstream sensor after the catalytic converter. This sensor mainly monitors converter health.
The rear oxygen sensor heater warms the sensor so it reports quickly. The computer measures heater current or resistance, and P0141 sets when the circuit is open, shorted, or out of range.
Because the rear sensor's main job is to check the catalytic converter, P0141 rarely affects how the engine runs. However, it prevents the catalyst monitor from completing, which can fail an emissions test.
Common causes (cheapest likely first)
- Failed heater in the rear sensor. Most common.
- Blown fuse. Check first.
- Damaged wiring. Road debris and heat can damage it.
Symptoms
- Check engine light
- Usually no noticeable symptoms
- Catalyst monitor shows not ready
DIY difficulty: Moderate
Rear sensors are under the car and often rusted in place.
Tools: OBD-II scanner, Oxygen sensor socket, Jack stands, Penetrating oil, Multimeter
Testing the heater
- With the engine off and the sensor unplugged, measure resistance across the two heater wires at the sensor. Compare with the specification.
- Check for battery voltage on the heater supply wire with the key on.
- Check the related fuse.
- If the heater reads open, replace the sensor.
Estimated repair cost
This is an estimate, built from typical parts price ranges plus labor hours times an assumed shop rate of $110 to $190 per hour. Actual prices vary by vehicle, region, and shop. Diagnosis fees are often extra.
| Repair | Parts | Labor | Estimate (low / high) |
|---|---|---|---|
| Rear oxygen sensor | $30 to $130 | 0.3 to 1.0 h | $30 + 0.3 × $110 = $63 $130 + 1.0 × $190 = $320 |
| Wiring repair | $5 to $40 | 0.5 to 1.5 h | $5 + 0.5 × $110 = $60 $40 + 1.5 × $190 = $325 |
Watch a repair video
Search YouTube for “P0141 fix” videos. Pick a recent video that matches your engine, and confirm the diagnosis before buying parts.
By make
This code works the same way on every make. See brand notes.
Repair manuals
Step-by-step service manuals with torque specs and wiring diagrams:
Haynes manuals Chilton manuals
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Related codes
Check for recalls
Before paying for a repair, enter your VIN in the NHTSA recall lookup. Emissions parts may also be covered by a federal emissions warranty; check your warranty booklet.
FAQ
Will P0141 cause P0420?
A faulty rear sensor can make the converter test unreliable, so fix P0141 first.
Is the rear sensor the same as the front?
Often not. Check the part number for the exact position.
Can I unplug the rear oxygen sensor?
No. That sets more codes and fails inspection.
How do I tell sensor 2 from sensor 1?
Sensor 1 is before the catalytic converter. Sensor 2 is after it.