OBD-II code · Powertrain (generic, extended)
P22AC O2 Sensor Positive Current Control Circuit Low (Bank 1 Sensor 2)
O2 positive current line on bank 1 sensor 2 stuck low — short to ground. A drifted or sluggish lambda sensor lets the mixture run lean or rich without correction — fuel economy and emissions suffer immediately.
Is it safe to drive with P22AC?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyShort to ground
- Less likelyConnector pins corroded - high contact resistance
- Less likelyHarness chafing through insulation
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–2.5 h
- Emissions test
- Likely to fail
- Parts involved
- Oxygen Sensor
Related codes
- P22ABO2 Sensor Positive Current Control Circuit/Open (Bank 1 Sensor 2)
- P22B9O2 Sensor Positive Current Control Circuit Low (Bank 2 Sensor 2)
- P22A9NOx Sensor Heater Sense Circuit High (Bank 1 Sensor 2)
- P22AANOx Sensor Heater Sense Circuit Intermittent (Bank 1 Sensor 2)
- P22ADO2 Sensor Positive Current Control Circuit High (Bank 1 Sensor 2)
- P22AEO2 Sensor Reference Voltage Circuit/Open (Bank 1 Sensor 2)
- P22AFO2 Sensor Reference Voltage Performance (Bank 1 Sensor 2)
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.