OBD-II Code · Sensors
P2273
HO2S Signal Stuck Lean (B2S2)
Severity
low
Lowest on our scale. Fix it when convenient.
Can you drive it
Only if running normally
A short trip to a shop may be reasonable if the light is steady and the car runs normally. Stop safely for a flashing light, severe shaking, overheating, loss of power, or another urgent warning. The code alone cannot confirm safety.
Indicative cost (USD)
$150–$400
Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.
Downstream O2 sensor on bank 2 stuck reading lean.
How a shop works this
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.
Note every code that is set, not just this one.
Codes that appear together usually narrow the cause faster than any one of them read alone.
Read the freeze frame — the conditions the fault was recorded under.
Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.
Confirm the fault is current rather than history.
Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.
Then work the likely-causes list in the order shown.
That order is what a shop checks first for this code — wiring and connections before the component they run to, because a connector costs nothing to inspect and is a common answer.
If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.
Common symptoms
- Check engine light
Likely causes
- Failed sensorMost common
- Exhaust leak before sensor
- Lean fuel condition
Read the full diagnostic procedureP2273 is the Bank 2 downstream O2 stuck-rich fault, mirroring P2271 on the right bank only.
P2273 is the Bank 2 downstream O2 stuck-rich fault, mirroring P2271 on the right bank only.
Cheapest-first ladder
- confirm the issue is bank-specific by overlaying Bank 1 and Bank 2 downstream traces under a 10-second decel fuel cut - both should drop below 0.3 V; if only Bank 2 stays high, the fault is real on that side.
- Pull Bank 2 long-term fuel trim and injector balance rates.
- Caveat: a contaminated Bank 2 sensor from oil burn will set P2273 even with perfect fueling - inspect the Bank 2 turbo center section for shaft play and oil weep before condemning the catalyst.
Vehicle-specific patterns2011 to 2014 Ford 6.7L Powerstroke set P2273 from Bank 2 injector copper-washer leak overfueling that cylinder; 2007 to 2012 Mercedes Sprinter OM642…
- 2011to 2014 Ford 6.7L Powerstroke set P2273 from Bank 2 injector copper-washer leak overfueling that cylinder;
- 2007to 2012 Mercedes Sprinter OM642 set the code from right-bank EGR cooler internal leak;
- 2011to 2016 Duramax LML throw P2273 when the Bank 2 downstream sensor is contaminated by DEF over-dosing;
- 2014to 2018 Ram EcoDiesel set P2273 from a Bank 2 piston ring failure consuming oil into the exhaust.
Estimated repair$130 to $4,200.
Look up another code
P2273 — frequently asked
What does a P2273 code mean?
Downstream O2 sensor on bank 2 stuck reading lean.
What causes a P2273 code?
Common causes: Failed sensor; Exhaust leak before sensor; Lean fuel condition.
What are the symptoms of a P2273 code?
Typical symptoms: Check engine light.
Is it safe to drive with a P2273 code?
Only if running normally. A short trip to a shop may be reasonable if the light is steady and the car runs normally. Stop safely for a flashing light, severe shaking, overheating, loss of power, or another urgent warning. The code alone cannot confirm safety. Estimated repair: $150-$400.
How do I diagnose a P2273 code?
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed. 1. Note every code that is set, not just this one. 2. Read the freeze frame — the conditions the fault was recorded under. 3. Confirm the fault is current rather than history. 4. Then work the likely-causes list in the order shown.
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