P2272O2 Sensor Signal Biased/Stuck Lean (Bank 2, Sensor 2)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2272 applies to V and flat engines with a separate catalyst and rear oxygen sensor on bank 2; that sensor fails to reach a rich reading when the ECM enriches bank 2. GM's 2016 tables (16OBDG05) set it if the voltage is still under 800 mV after 68 g of air during forced enrichment (Type B). GM's Bosch-based 2005 2.8 and 3.6 V6 first wait for 100 s below about 0.58 to 0.66 V, then ramp up the fuel and fail the sensor if it has not risen 10 s after the enrichment limit. Ford uses the same 0.42 V limit as on bank 1. Mazda found oil from a leaking oil pressure switch inside connector C-34 on the 2007 to 2015 CX-9, stored with P2A04, and fixed it with a new switch and a cleaned connector. If only bank 2 reports a fault, comparing its data with bank 1 narrows it down.
- What you may notice
- Malfunction indicator lamp on
- Catalyst monitor for bank 2 not completing
- Likely causes
- LikelyBank 2 rear oxygen sensor aged or contaminated
- PossibleEngine oil in the sensor connector, for example from a leaking oil pressure switch
- PossibleExhaust leak on bank 2 ahead of the rear sensor
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €0 – €300
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.