HO2S Sensor Correlation Bank 2 Sensor 1/Bank 2 Sensor 2
Pre- and post-cat oxygen sensors on bank 2 do not correlate as expected — typical sign of catalyst inefficiency or one failed sensor.
Affected components
- Oxygen sensor b2s1
- Oxygen sensor b2s2
- Catalyst
Common causes
- High likelihood: Catalyst aged or contaminated
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- A drive cycle may be required after repair
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.