Powertrain
generic / SAE
P0143
O2 Sensor Circuit Malfunction (Bank 1 Sensor 3)
The ECU detects a general electrical fault on the third oxygen sensor in the bank 1 exhaust path (typically located after a second catalyst on diesel or large engines with multi-cat exhausts).
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number1 / 43
Possible causes
- Sensor aged or failed high
- Sensor wiring open or shorted medium
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Inspection / repair
- Difficulty: easy
- DIY: possible
- Estimated cost: 80–350 €
- Estimated time: 0.3–1.5 h
- Component: oxygen sensor b1s3
- Component: oxygen sensor wiring
- MIL / check engine light
- emissions-relevant
- drive cycle required
Sources
References
sae:J2012