Code result
P2A01
O2 Sensor Circuit Range/Performance Bank 1 Sensor 2
Moderate severity
What it means
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?
Use caution
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.
Most likely causes
Sensor aging
highOne of the most commonly reported causes for this code — check this first.
Catalyst aging
mediumA plausible cause — test and verify before replacing parts.
Sensor element aged beyond calibration window
lowLess common, but worth ruling out after the more likely causes.
Related help
Get the full diagnosis
Add your vehicle and see step-by-step repair help, recalls, and TSBs in Wrenchify.
Diagnose P2A01 freeNo credit card required