P0151moderate severityPowertrain
O2 Sensor Circuit Low Voltage Bank 2 Sensor 1
on 2010 Cadillac CTS 3.0L V6 · AWD
What this code means
The upstream O2 sensor voltage on Bank 2 is staying low.
Symptoms
- Check Engine Light
- Lean running Bank 2
- Rough idle
Common causes
- Vacuum leak Bank 2
- Faulty sensor
- Exhaust leak
- Low fuel pressure
Diagnostic steps
- Check vacuum leaks Bank 2
- Monitor sensor voltage
- Test fuel pressure
Repair notes
Fix leak or replace sensor.
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