O2 Sensor Pumping Current Trim Circuit Low Bank 2 Sensor 1
The wide-band trim resistor circuit on bank 2 sensor 1 reads low. Air-fuel feedback gain on bank 2 is wrong, causing rich or lean offsets.
Affected components
- Oxygen sensor wideband b2s1
- Sensor calibration resistor
- Wiring harness
Common causes
- High likelihood: Short in the calibration trim resistor
- Medium likelihood: Water intrusion in the sensor connector
- Low likelihood: Connector pins corroded - high contact resistance
Possible symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
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.