17510moderate severityPowertrain
O2 Sensor Circuit Bank 1 Sensor 2
on 2009 Audi A8 4.2L V8 · AWD
What this code means
The downstream oxygen sensor on bank 1 (after the catalytic converter) is reading out of range or not responding. Equivalent to OBD code P0136.
Symptoms
- Check engine light on
- Increased fuel consumption
- Failed emissions test
Common causes
- Faulty downstream O2 sensor
- Damaged sensor wiring or connector
- Exhaust leak near sensor
- Blown sensor fuse
Diagnostic steps
- Read live O2 sensor voltage data
- Inspect sensor wiring and connector
- Check for exhaust leaks near sensor
- Replace O2 sensor if unresponsive
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