P1141 — HO2S Bank 1 Sensor 2 Average Voltage Level

Diagnostic algorithm

1. Clear codes and perform a test drive to verify P1141 returns and capture freeze-frame data.
2. Visually inspect the Bank 1 Sensor 2 connector and harness. Repair any obvious wiring damage or corrosion first.
3. With a scan tool, monitor Bank 1 Sensor 1 and Sensor 2 voltages during warm engine idle and light load. Note whether Sensor 2 is averaging near expected value and whether it mirrors or remains steady compared to Sensor 1.
4. Backprobe the sensor signal wire to measure voltage with a digital multimeter or oscilloscope. Confirm signal is within expected range and behavior (not stuck high/low or noisy).
5. Check the sensor heater circuit: verify supply voltage with key on and measure heater resistance to confirm continuity and correct resistance per spec.
6. Check for exhaust leaks upstream of the downstream sensor and repair if present. Re-test after repairs.
7. If wiring and heater are good but the sensor signal is abnormal, replace the downstream HO2S (Bank 1 Sensor 2) with a correct OEM or equivalent sensor.
8. After repair, clear codes and re-check operation. Confirm long-term and short-term fuel trims and catalyst monitors return to normal and code does not reappear.
9. If code persists after sensor replacement and harness checks, consider catalytic converter efficiency testing and, if needed, inspect or test PCM for faults as a last resort.