OBD-II Code · Sensors
P2272
HO2S Signal Stuck Lean (Bank 2 Sensor 2)
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–$500
Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.
Downstream B2S2 stuck 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
Read the full diagnostic procedureP2272 is the Bank 2 downstream O2 stuck-lean fault, only present on V-bank diesels with dual post-cat sensors.
P2272 is the Bank 2 downstream O2 stuck-lean fault, only present on V-bank diesels with dual post-cat sensors.
Cheapest-first ladder
- confirm both banks first - if Bank 1 is healthy and only Bank 2 sensor 2 is pinned lean, inspect the Bank 2 exhaust path from manifold to mid-pipe with a smoke machine at 0.5 psi, since even a hairline crack in the Y-pipe or a leaking up-pipe gasket will pull ambient air across the sensor tip.
- Caveat: a sticking Bank 2 EGR valve will lean out the right bank only and set P2272 without any sensor fault - always pull EGR position versus commanded data before replacing the sensor.
Vehicle-specific patterns2008 to 2010 Ford 6.4L Powerstroke set P2272 from cracked Bank 2 up-pipe at the flange near the turbo pedestal; 2011 to 2016 Duramax LML throw the co…
- 2008to 2010 Ford 6.4L Powerstroke set P2272 from cracked Bank 2 up-pipe at the flange near the turbo pedestal;
- 2011to 2016 Duramax LML throw the code from a leaking Bank 2 EGR cooler diluting exhaust;
- 2011to 2019 Ford 6.7L Powerstroke set P2272 when the Bank 2 sensor heater fails after a regen cycle;
- 2007to 2014 Mercedes ML320/350 BlueTEC OM642 set the code from a cracked Bank 2 manifold.
Estimated repair$120 to $1,800.
Look up another code
P2272 — frequently asked
What does a P2272 code mean?
Downstream B2S2 stuck lean.
What causes a P2272 code?
Common causes: Failed sensor; Exhaust leak before sensor.
What are the symptoms of a P2272 code?
Typical symptoms: Check engine light.
Is it safe to drive with a P2272 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-$500.
How do I diagnose a P2272 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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