P0141 Code: O2 Sensor Heater (B1S2) — Causes & Fix
P0141 means a fault in the heater circuit of the downstream oxygen sensor (bank 1, sensor 2) — the heater that brings the sensor to operating temperature.
- Applies to
- All OBD-II vehicles (any make or model)
- Est. repair cost
- $40 – $300
- Time to fix
- 30 minutes – 2 hours
What it means
Typical causes are a failed heater element in the O2 sensor, a blown fuse, or wiring/connector faults. P0141 is a generic OBD-II powertrain code defined in the SAE J2012 standard, so it applies to virtually any 1996-or-newer petrol car or light truck regardless of make. Fix the underlying fault, then clear the code with an OBD-II scan tool — it will return if the problem isn't resolved.
Symptoms
- Check engine light on
- Little effect on drivability
- May fail an emissions readiness check
How to fix it
- 1
Check the heater fuse and wiring
1. Confirm the O2 heater fuse is good. 2. Inspect the connector and wiring.
- 2
Replace the downstream O2 sensor
1. Measure the heater circuit resistance. 2. Replace the sensor if the heater is open, then clear the code.
Frequently asked questions
Is P0141 serious?
Drivability is usually fine, but it blocks emissions readiness and should be fixed to pass inspection.
Last updated July 19, 2026
Guidance only — always consult a qualified professional or the official service manual before carrying out repairs.