Fault-Code Library · Oxygen sensing
P0141: Oxygen sensor heater circuit, bank 1 sensor 2
The downstream oxygen sensor heater circuit is not reaching expected operation.
Common symptoms
- •Engine warning light
- •Catalyst monitor not ready
- •Usually little drivability change
Likely causes
- •Failed downstream oxygen sensor heater
- •Damaged exhaust-area wiring
- •Fuse or relay issue
- •Connector corrosion
First checks
- •Inspect sensor wiring and connector
- •Check heater power and ground
- •Confirm catalyst-related codes are not the root cause
Important
A downstream heater fault can prevent emissions readiness even if the car drives normally.
A fault code identifies a detected condition, not a failed part. Confirm manufacturer-specific subcodes and live data.
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