Powertrain
generic / SAE
P0157
O2 Sensor Circuit Low Voltage (Bank 2 Sensor 2)
The ECU detects abnormally low voltage from the downstream O2 sensor on bank 2. Indicates persistently lean exhaust past the catalyst, open sensor or wiring shorted to ground.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number1 / 57
Possible causes
- Lean condition on bank 2 high
- Signal wire shorted to ground medium
- Downstream O2 sensor failed 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 b2s2
- Component: oxygen sensor wiring
- Component: catalytic converter bank2
- MIL / check engine light
- emissions-relevant
- drive cycle required
Sources
References
sae:J2012