Powertrain
Definition only
Lights the check engine lamp
P2A03: O2 Sensor Circuit Range/Performance Bank 2 Sensor 1
Standardized SAE J2012 code · P2Axx codes
What does P2A03 mean?
The front oxygen sensor on bank 2 reacts too slowly or shows insufficient signal swing during closed-loop fuel control.
The code tells you which monitor failed, not which part is broken. Test before replacing parts.
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Common causes
- High Sensor aging
- Medium Sensor contamination
- Low Sensor element aged beyond calibration window
Likelihood is a general estimate across vehicles; your make and model may differ.
Add your car to see reports of P2A03 on the same make and model first.
P2A03 in the community
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Describe your P2A03 problemRelated codes
- P2A00 O2 Sensor Circuit Range/Performance Bank 1 Sensor 1
- P2A01 O2 Sensor Circuit Range/Performance Bank 1 Sensor 2
- P2A02 O2 Sensor Circuit Range/Performance Bank 1 Sensor 3
- P2A04 O2 Sensor Circuit Range/Performance Bank 2 Sensor 2
- P2A05 O2 Sensor Circuit Range/Performance Bank 2 Sensor 3
- P2A06 O2 Sensor Circuit Range/Performance Bank 1 Sensor 4
- P2A07 O2 Sensor Circuit Range/Performance Bank 2 Sensor 4