Ford Focus Oxygen Sensor BV61-9G444-AA 0258010246 Rear Oxygen Specific

If your Ford Focus exhibits idle instability, higher fuel consumption, exhaust smell, or the engine diagnostic light with codes such as P0136/P0141, it indicates the rear oxygen sensor has aged or failed and can no longer accurately monitor the oxygen content after the catalytic converter. This sensor's normal operation is to provide real-time feedback of remaining oxygen in the exhaust to help the ECU precisely adjust the air–fuel ratio, ensuring efficient catalyst purification and maintaining engine power and fuel economy. This product is rear-oxygen sensor-only, OEM BV61-9G444, fits Ford Focus (2012–2018, 1.6L/2.0L, etc.). Installation should be performed with the engine cold; use a dedicated oxygen sensor socket to avoid thread damage; apply anti-seize compound to threads before installation and tighten to the specified torque to prevent leaks or signal interference.