O2 Sensor Circuit (Bank 2, Sensor 1)
The P0150 code means the vehicle's onboard diagnostic system has detected: O2 Sensor Circuit (Bank 2, Sensor 1). This is a serious severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- easy
- Estimated cost
- $50-$200
Test O2 sensor voltage (should fluctuate 0.1-0.9V). Do not replace a $150 sensor without confirming it is actually bad first.
Shows real-time O2 sensor readings on your phone. See if the sensor is lazy, stuck, or actually working before spending money.
Affiliate links — we earn a commission at no extra cost to you.
Common Symptoms
- Check Engine Light on
- Poor fuel economy
- Rough running
- Rich or lean condition
- Failed emissions
Probable Causes (Ranked by Likelihood)
- Failed Bank 2 upstream O2 sensor Very High
- Wiring fault to Bank 2 sensor High
- Exhaust leak near Bank 2 sensor Moderate
- Sensor heater failure Moderate
Common Fixes by Vehicle
What techs usually find when diagnosing P0150 on specific vehicles — tap your vehicle for the fix and the exact part:
2005-2014 Ford F-150/Expedition/Mustang 4.6L/5.0L/5.4L Easy DIY
Bank 2 sensor 1 (upstream, passenger side on most V8s) malfunction — replace with an OE-quality Motorcraft unit or Denso OEM. Check for exhaust manifold cracks that let ambient air dilute the reading. Don't use universal-fit sensors.
Labor: 30-45 min2005-2014 GM 5.3L/6.0L LS (Silverado, Tahoe, Yukon) Easy DIY
Bank 2 upstream O2 failure on LS-series truck engines — replace with an OE-quality ACDelco unit. Confirm no exhaust leak at broken manifold studs (common on 5.3L after 100K). Verify PCM 5V reference is stable.
Labor: 30-45 min2007-2014 Toyota Tundra/Sequoia 5.7L V8 Easy DIY
Bank 2 sensor 1 air/fuel sensor malfunction — replace with an OE-quality Denso unit A/F sensor only. Aftermarket A/F sensors notoriously fail on Toyota V8 applications within 20K miles.
Labor: 30-45 minFrequently Asked Questions
How do I find Bank 2 Sensor 1 on a V8?
On most American V8s (Ford, GM, Dodge), Bank 2 is the passenger side. Sensor 1 is the sensor before the catalytic converter on that side -- usually located on the exhaust manifold or just downstream of it.
What actually makes the computer set an oxygen sensor code?
The OBD II regulation requires four separate detections for an oxygen sensor (Title 13 CCR 1968.2, section (e)(7.2)): deterioration in voltage, response rate or amplitude that would push emissions past 1.5 times the FTP standards; loss of circuit continuity; out-of-range values; and the case where the sensor has degraded enough that the fuel system stops using it and falls back to open loop. A sensor can therefore set a code while still producing a signal that looks plausible on a scan tool. This is the threshold the monitor is designed around, not a description of your specific fault — the regulation says what the system must detect, not how to find it on your vehicle.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
-
Identify Bank 2 on your engine (the side without cylinder 1). Locate the upstream O2 sensor on that side.
-
Monitor Bank 2 Sensor 1 voltage: should switch 0.1-0.9V at idle.
-
Compare Bank 1 and Bank 2 fuel trims: if Bank 2 is significantly different, focus diagnosis there.
-
Test heater, wiring, and sensor as with P0130.
Sources 3
This page is built from documented references. Verify against your own service info before repair work.
- California Code of Regulations, Title 13 section 1968.2 (OBD II)malfunction criteria, section (e)
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
Commonly Affected Vehicles
- Ford F-150 and Mustang V8 (Bank 2 passenger side)
- Toyota 4Runner and Tundra V8
- Chevrolet Silverado and Tahoe V8
- Dodge Ram 5.7L HEMI
- Nissan Titan
Related Codes
See All Codes & Fixes for Your Vehicle
Explore More
Was this helpful?
Send this to whoever is fixing the car — your mechanic, or the person asking what the light means.