P0160: O2 Sensor Circuit No Activity Detected (Bank 2, Sensor 2)
TL;DR
P0160 = O2 sensor circuit no activity (Bank 2, Sensor 2). Severity: low. Top causes: failed downstream O2 sensor (50%), wiring/connector (25%), exhaust leak (15%), heater fault (10%). Bank 2 = side opposite cylinder #1.
Can I keep driving with P0160?
IF it’s just P0160 → safe to drive; it mainly affects emissions monitoring, not drivability. Fix it to pass inspection and clear the light.
Symptoms
- Check engine light on
- Usually no drivability change
- May fail emissions/inspection
- Slightly worse fuel economy in some cases
- No performance loss
Top causes (ranked by probability)
| Likely cause | Probability | Notes |
|---|---|---|
| Failed downstream O2 sensor | 50% | |
| Wiring or connector fault | 25% | |
| Exhaust leak near the sensor | 15% | |
| Heater fault preventing operation | 10% |
What does P0160 mean?
Technical explanation
The downstream (post-cat) O2 sensor monitors catalytic converter efficiency. P0160 sets when the Bank 2, Sensor 2 signal shows no activity — a flat or non-responsive output. Causes include a failed sensor, an open/short or corroded connector in the wiring, an exhaust leak upsetting readings, or a heater fault preventing the sensor from reaching temperature. It affects emissions monitoring more than how the car drives.
In simple terms
The rear oxygen sensor (after the catalytic converter) on one side checks that the converter is working. P0160 means that sensor on Bank 2 isn’t responding — usually a dead sensor or a wiring problem. The car drives normally; it’s mostly an emissions-monitoring issue to fix so it passes inspection.
How to diagnose P0160 (step by step)
- Confirm the bank/sensor. Bank 2 is the side without cylinder #1; Sensor 2 is downstream (after the cat).
- Read O2 live data. A flat, non-responsive signal confirms no activity.
- Inspect wiring and connector. Look for opens/shorts and corrosion.
- Check for exhaust leaks. A leak near the sensor can upset the reading.
- Replace the downstream O2 sensor. If wiring and exhaust are good, replace the sensor.
Repair options & cost
- Replace the Bank 2 downstream O2 sensor
- Repair the wiring/connector
- Repair an exhaust leak
🔧 Doing it yourself? Buy the part: Oxygen (O2) sensor
| DIY cost | $30–$200 |
|---|---|
| Workshop cost | $150–$400 |
| Repair time | 30–60 minutes |
Costs are local ballpark ranges and vary by region and vehicle.
Tools you’ll need
Scan your car: recommended OBD-II scanners →Vehicle-specific notes
- Bank 2 is the side of the engine WITHOUT cylinder #1 — confirm before buying a sensor.
- Sensor 2 is the downstream (post-catalytic-converter) sensor.
- P0160 mirrors P0140 (Bank 1, Sensor 2 no activity); check for exhaust leaks too.
Common mistakes to avoid
- Replacing the upstream sensor by mistake
- Buying for the wrong bank
- Overlooking an exhaust leak
- Ignoring a corroded connector
Frequently asked questions
What does P0160 mean?
The downstream oxygen sensor on Bank 2 (after the catalytic converter) shows no activity — usually a failed sensor, a wiring problem, or an exhaust leak.
Which sensor is Bank 2, Sensor 2?
Bank 2 is the cylinder bank without cylinder #1; Sensor 2 is the downstream sensor after the catalytic converter. Confirm before buying so you replace the right one.
Is P0160 safe to drive with?
Yes. It mainly affects emissions monitoring, not how the car drives. Fix it to pass inspection and clear the light.
P0160 summary
| Meaning | O2 no activity (Bank 2, Sensor 2) |
|---|---|
| Severity | Low |
| Safe to drive? | Yes — emissions related |
| Top cause | Failed downstream O2 (50%) |
| DIY cost | $30–$200 |
| Shop cost | $150–$400 |