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.
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.
Common causes
- high
Sensor aging
One of the most commonly reported causes for this code — check this first.
Typical part cost: $130-440
- medium
Catalyst aging
A plausible cause — test and verify before replacing parts.
Typical part cost: $130-440
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First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
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Related codes
See related trouble codes
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Frequently asked questions
What does P2A01 mean?
P2A01 means "O2 Sensor Circuit Range/Performance Bank 1 Sensor 2". It is a generic OBD-II code that points to a fault in the auxiliary emission controls.
What are the most common causes of P2A01?
sensor aging; catalyst aging; sensor element aged beyond calibration window — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.
Can I keep driving with this code?
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.
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