Possible causes – Faulty Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1– Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit fuse– Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit open shorted to ground– Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit poor electrical connection– Faulty Engine Control Module (ECM) Tech description The…