Ford Mondeo Rear Oxygen Sensor 1S7F-9G444-BA Upgraded Exhaust Gas Monitoring System

Ford Mondeo (2007–2014) 2.0L/2.3L/2.5L and Mondeo Ghia series; rear oxygen sensor compatible with OEM 1S7F-9G444-BA. Monitors exhaust oxygen content after catalyst, sends signal to ECU to optimize air–fuel ratio; prevent emissions over limits or engine fault lights. Replacement: disconnect battery negative, use dedicated oxygen sensor socket to remove old part to avoid thread damage; install torque 30–40 N·m; apply anti-seize. This upgraded sensor is compatible with factory harness and improves emissions monitoring, especially for high-mileage or pre-test maintenance.