P0160 — Oxygen sensor circuit no activity detected — bank 2, sensor 2

P0160 indicates absence of expected signal activity under the monitor conditions for bank 2, sensor 2. Sensor 2 is usually after the first catalyst; some exhaust layouts also have sensor 3. A fixed reading while cold does not establish a fault by itself; monitor enable conditions matter.

Affected system: Powertrain

Symptoms

• Engine warning lamp and a stored code.
• Driveability symptoms are often absent; emissions inspection issues may occur.

Possible causes

• Open or shorted signal circuit, or an unreliable connector contact.
• Inactive or contaminated sensing element; insufficient heating can delay readiness.

What to check

• Confirm B2S2 in the engine diagram and save related codes and freeze-frame data before clearing anything.
• With the exhaust cold, inspect the B2S2 harness for melted insulation, rubbing, water in the connector and loose terminals.
• Confirm heating and monitor conditions; establish whether the signal changes during the response test specified by the manufacturer.
• A relatively steady downstream signal can be normal; distinguish catalyst-related stability from failure to respond during the OEM test.
• After correcting the confirmed fault, repeat the OEM monitor conditions and check for code recurrence, beyond merely extinguishing the lamp.

Also written as: P0160-00, P016000, PO160 (some scan tools add the fault-type byte, e.g. -00).