Fuel & air metering · Powertrain · generic (SAE-defined)
P0150: O2 Sensor Circuit (Bank 2 Sensor 1)
P0150 means there is a general fault in the upstream oxygen sensor circuit on bank 2, the side of the engine opposite cylinder 1 on V-type or flat engines.
Standard title per SAE J2012 / ISO 15031-6 · Updated 2026-11-07 · By CarWhere Research
How P0150 sets
On engines with two cylinder banks, the powertrain control module (PCM) uses a separate upstream oxygen (O2) sensor, located before the catalytic converter, for each bank. Once warm and in closed loop, it expects the bank 2 sensor 1 signal to be in a plausible range and to respond to fuel changes. If the signal is electrically faulty or implausible for long enough, P0150 sets. Criteria are manufacturer-specific.
Common causes of P0150
Roughly most likely first; the actual cause depends on the vehicle and needs testing to confirm.
- Failed bank 2 sensor 1 oxygen sensor
- Heat-damaged or chafed wiring near the exhaust manifold
- Corroded or loose connector
- Exhaust manifold leak on bank 2
- Fueling fault on bank 2 skewing the reading
P0150 symptoms
- Check engine light on
- Reduced fuel economy
- Occasional rough idle
- Often no noticeable drivability change
How P0150 is diagnosed
- Scan for codes and freeze frame; look for bank 2 fuel trim or misfire codes.
- Identify bank 2 as the side without cylinder 1, then locate its upstream sensor before the converter.
- Inspect wiring and connector, which often route near hot exhaust components.
- Check for exhaust manifold or gasket leaks on bank 2.
- Compare bank 1 and bank 2 sensor activity on live data with the engine warm.
- Test the sensor circuits for opens and shorts.
Typical fixes for P0150
- Replace the bank 2 sensor 1 oxygen sensor
- Repair damaged wiring or connector
- Repair bank 2 exhaust manifold leaks
- Correct any fueling problem affecting bank 2
Replace parts only after testing confirms the cause — a code names the circuit or condition that failed a check, not necessarily the faulty part. We don’t publish per-repair prices; for what households actually spend on upkeep, see car repair costs.
Related codes & warning lights
P0150 FAQ
What does code P0150 mean?
P0150 means there is a general fault in the upstream oxygen sensor circuit on bank 2, the side of the engine opposite cylinder 1 on V-type or flat engines. The standard definition is "O2 Sensor Circuit (Bank 2 Sensor 1)."
Can I drive with a P0150 code?
In most cases yes for a short while, but fuel control on that side of the engine may be less accurate. Get it diagnosed within days to protect fuel economy and the catalytic converter.
Does my car have a bank 2?
Only engines with two cylinder heads, such as V6, V8 and flat engines, have a bank 2. Inline four- and six-cylinder engines normally have only bank 1, so a bank 2 code on them is unusual and worth verifying.
Is P0150 the same problem as P0130?
It is the same type of fault, but on the opposite side of the engine. P0130 is the bank 1 upstream sensor; P0150 is the bank 2 upstream sensor.
Keep researching
Engine guides by brand (known issues, specs)
More fuel & air metering codes
Sources
- SAE J2012 — Diagnostic Trouble Code Definitions (standard code titles)
- ISO 15031-6 — Road vehicles: communication between vehicle and external equipment for emissions-related diagnostics, Part 6: Diagnostic trouble code definitions
- U.S. EPA — Vehicle Emissions Inspection and Maintenance (I/M) programs
- U.S. EPA, 40 CFR 86.1806-17 — Federal onboard diagnostics requirements for light-duty vehicles
- California Air Resources Board — On-Board Diagnostic (OBD) Program
General information written by CarWhere Research, not a diagnosis of your vehicle. Manufacturers can add their own sub-definitions and test conditions; confirm with the factory service information for your year, make and model. Before paying for a repair, check NHTSA for open recalls and your warranty booklet: federal law requires an emissions warranty on major emission-control parts such as the catalytic converter and engine computer.