P2272 code meaning
O2 Sensor Signal Biased/Stuck Lean (Bank 2, Sensor 2)
Powertrain system Generic code P22xx codes Check engine light
What P2272 means
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.
P2272 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.3 to 2 hours
- Clears after repairAfter a drive cycle
Symptoms of P2272
- Malfunction indicator lamp on
- Catalyst monitor for bank 2 not completing
Common causes of P2272
- Most 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
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Oxygen sensor downstreamOxygen sensor wiringCatalytic converter
What each part of P2272 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 2 | Area: fuel and air metering (injector circuit). |
| 72 | The exact fault in that area. |
What to do next
- Note P2272 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2272
What does P2272 mean?
P2272 means "O2 Sensor Signal Biased/Stuck Lean (Bank 2, Sensor 2)". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P2272?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P2272 fail an emissions test?
Yes, it can. P2272 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2272 to fix?
Difficulty: medium. A typical repair takes 0.3 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P2272 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.