P0154: O2 Sensor Circuit No Activity Detected — Bank 2 Sensor 1
What to do
Expect poorer economy and emissions. If a heater code is also stored, that is likely the root cause.
What this code means
The upstream bank 2 sensor signal is not moving. Check for an accompanying heater code first — a sensor that never reaches operating temperature produces exactly this flat trace while being otherwise healthy.
Likely causes
Start here
- Faulty oxygen sensor · easy
- Failed oxygen sensor heater element · easy
- Open circuit in sensor wiring · moderate
- Corroded or loose connector · easy
Less common
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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