Powertrain
generic / SAE
P0166
O2 Sensor Circuit No Activity / Slow Response (Bank 2 Sensor 3)
The ECU detects no switching or too slow a response from the third O2 sensor on bank 2. Typically aged or poisoned sensor or weak heater.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number1 / 66
Possible causes
- Sensor aged or poisoned high
- Heater circuit weak 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 b2s3
- Component: oxygen sensor heater circuit
- MIL / check engine light
- emissions-relevant
- drive cycle required
Sources
References
sae:J2012