OBD-II code · Powertrain (generic)
P0154 O2 Sensor Circuit No Activity / Slow Response (Bank 2 Sensor 1)
The ECU detects no switching activity or too slow a response from the upstream O2 sensor on bank 2. Typically aged or poisoned sensor, weak heater, or upstream exhaust leak.
Is it safe to drive with P0154?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySensor aged or poisoned
- PossibleHeater circuit weak
- PossibleExhaust leak before sensor
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.3–1.5 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Oxygen Sensor B2s1, Oxygen Sensor Heater Circuit, Exhaust Manifold Bank2
Related codes
- P0134O2 Sensor Circuit No Activity / Slow Response (Bank 1 Sensor 1)
- P0140O2 Sensor Circuit No Activity / Slow Response (Bank 1 Sensor 2)
- P0146O2 Sensor Circuit No Activity / Slow Response (Bank 1 Sensor 3)
- P0160O2 Sensor Circuit No Activity / Slow Response (Bank 2 Sensor 2)
- P0166O2 Sensor Circuit No Activity / Slow Response (Bank 2 Sensor 3)
- P0151O2 Sensor Circuit Low Voltage (Bank 2, Sensor 1)
- P0152O2 Sensor Circuit High Voltage (Bank 2, Sensor 1)
- P0153O2 Sensor Circuit High Voltage (Bank 2 Sensor 1)
- P0155O2 Sensor Heater Circuit Malfunction (Bank 2, Sensor 1)
- P0156O2 Sensor Circuit Malfunction (Bank 2, Sensor 2)
- P0157O2 Sensor Circuit Low Voltage (Bank 2 Sensor 2)
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.