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.
Medium severity. Can I keep driving?Yes, you can normally drive in moderation, but get it repaired soon: you will use more fuel and the catalytic converter can be damaged over time.
Bank 2 is the side without cylinder 1, so it only exists on V or boxer engines. Sensor 1 is the oxygen sensor before the catalytic converter.
Symptoms
- Check engine light on
- No mixture control (open loop), higher consumption
- Higher emissions, possible emissions test failure
Most likely causes
- Open or high-resistance signal or ground wire, connector loose or corroded
- Sensor faulty (cell high-resistance, worn out)
- Sensor heater faulty – sensor does not get hot enough
- Control module bias or measuring circuit faulty
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It affects emissions.
What each character of P0154 means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- 1: Air and fuel
- 54: Specific fault in that system
Frequently asked questions
Can I keep driving with code P0154?
Yes, you can normally drive in moderation, but get it repaired soon: you will use more fuel and the catalytic converter can be damaged over time.
What causes code P0154?
The most common causes are: open or high-resistance signal or ground wire, connector loose or corroded; sensor faulty (cell high-resistance, worn out); sensor heater faulty – sensor does not get hot enough.
Related codes
- P0134O2 Sensor Circuit No Activity Detected Bank 1 Sensor 1
- P0153O2 Sensor Circuit Slow Response Bank 2 Sensor 1
- P0155O2 Sensor Heater Circuit Bank 2 Sensor 1
- P0151O2 Sensor Circuit Low Voltage Bank 2 Sensor 1
- P0152O2 Sensor Circuit High Voltage Bank 2 Sensor 1
- P2240O2 Sensor Positive Current Control Circuit/Open (Bank 2 Sensor 1)
Sources
- law.cornell.edu: 13 CCR 1968.2
- saabwisonline.com: dtc p0134 p0140 p0154 or p0160 lf1 lfw
- newtonnet.co.uk: fordobd2012
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.