O2 Sensor Circuit High Voltage Bank 1 Sensor 4

Common symptoms

What you'll notice

• Check the wiring and connections of the O2 sensor in Bank 1 Sensor 4.
• Inspect the O2 sensor for any damage or signs of wear, and replace if necessary.
• Clean any debris or corrosion from the O2 sensor connectors.
• Update the vehicle's software or reprogram the engine control module (ECM) to ensure proper communication with the O2 sensor.
• If all else fails, consider replacing the ECM or the entire O2 sensor.

Common causes

Most likely first

1. Faulty oxygen sensor in bank 1
2. Malfunctioning wiring or connectors in the oxygen sensor circuit
3. Issues with the engine control module (ECM) or powertrain control module (PCM)
4. Vacuum leaks in the intake manifold or exhaust system
5. Fuel delivery problems such as a clogged fuel injector or fuel filter

How to diagnose & fix

Work through it in order

1. Check engine light illuminates on the dashboard
2. Decreased fuel efficiency and increased fuel consumption
3. Rough idle or stalling when the engine is at idle
4. Engine misfires or hesitation during acceleration
5. Increased emissions and foul smell from the exhaust