OBD-II code · Powertrain (generic, extended)
P2A01 O2 Sensor Circuit Range/Performance Bank 1 Sensor 2
The rear oxygen sensor on bank 1 does not show the expected slow steady-state behaviour after the catalyst. Either the sensor is degraded or the catalyst itself behaves abnormally.
Is it safe to drive with P2A01?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySensor aging
- PossibleCatalyst aging
- Less likelySensor element aged beyond calibration window
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
- 0.5–1.5 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Oxygen Sensor, Catalytic Converter
Related codes
- P2A00O2 Sensor Circuit Range/Performance Bank 1 Sensor 1
- P2A02O2 Sensor Circuit Range/Performance Bank 1 Sensor 3
- P2A03O2 Sensor Circuit Range/Performance Bank 2 Sensor 1
- P2A04O2 Sensor Circuit Range/Performance Bank 2 Sensor 2
- P2A05O2 Sensor Circuit Range/Performance Bank 2 Sensor 3
- P2A06O2 Sensor Circuit Range/Performance Bank 1 Sensor 4
- P2A07O2 Sensor Circuit Range/Performance Bank 2 Sensor 4
- P28F9Exhaust Pressure Too Low Bank 1
- P28FAExhaust Pressure Too Low Bank 2
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.