P0154O2 Sensor Circuit No Activity Detected Bank 2 Sensor 1
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- The oxygen sensor before the catalytic converter on bank 2 (sensor 1) is the main control sensor for the mixture. It is either a switching sensor (about 0.1 V lean to 0.9 V rich) or a wide-band sensor that works with a pump current evaluated by an interface chip. Bank 2 exists only on engines with two exhaust manifolds. P0154 is the bank 2 counterpart of P0134: the sensor delivers no moving signal and the control module only sees its own bias voltage. On GM's 3.0/3.6 V6 the code is set when the signal stays at 350–550 mV after heater warm-up, within about 15 s, in closed loop after 150 s of running; two trips. Ford's Bosch wide-band systems have used P2240 instead since 2011. A failed heater (P0155) can also lead to this code. A stored code usually switches mixture control to open loop and suspends adaptation and converter monitoring.
- What you may notice
- Check engine light on
- No mixture control (open loop), higher consumption
- Higher emissions, possible emissions test failure
- Likely causes
- LikelyOpen or high-resistance signal or ground wire, connector loose or corroded
- LikelySensor faulty (cell high-resistance, worn out)
- PossibleSensor heater faulty – sensor does not get hot enough
- RareControl module bias or measuring circuit faulty
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €50 – €350
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.