OBD-II code · Powertrain (generic, extended)
P2B8A Intake Air O2 Sensor Circuit High Voltage Bank 1
Voltage on the intake air oxygen sensor signal line on bank 1 is above the expected window. 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 P2B8A?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySignal wire shorted to B+
- PossibleOpen intake air O2 sensor
- Less likelyConnector pins corroded - high contact resistance
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.5–3 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Intake Air O2 Sensor B1, Intake Air O2 Sensor Heater B1, Wiring Harness, Ecm
Related codes
- P2B87Coolant Pump A Underspeed
- P2B88Intake Air O2 Sensor Circuit Bank 1
- P2B89Intake Air O2 Sensor Circuit Low Voltage Bank 1
- P2B8BIntake Air O2 Sensor Heater Control Circuit/Open Bank 1
- P2B8CIntake Air O2 Sensor Heater Control Circuit Range/Performance Bank 1
- P2B8DIntake Air O2 Sensor Heater Control Circuit Low Bank 1
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.