P0164
O2 Sensor Circuit Low Voltage (Bank 2 Sensor 3)
The ECU detects abnormally low voltage from the third O2 sensor on bank 2. Indicates lean exhaust, open sensor or wiring shorted to ground.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: easy
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Common causes
Ordered by how often each turns out to be the cause.
- Lean exhaust conditionCommon
- O2 sensor failedPossible
- Connector pins corroded - high contact resistanceLess likely
Parts involved
- Oxygen Sensor B2s3
- Oxygen Sensor Wiring
P0164 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.