Ford Rear Oxygen Sensor 234-4609 / YL8Z-9G444-AC / 234-4610, AIUSLN Precision Replacement

Ford Focus, Escape, Mondeo and other models’ rear oxygen sensor (OEM YL8Z-9G444) located after the catalytic converter monitors exhaust oxygen content and feeds data to the engine control unit to precisely adjust the air-fuel ratio, ensuring emissions compliance and fuel economy. Compatible with 234-4609, 234-4610, 234-4071 and other references. Installation is moderate; recommended labor 30–45 minutes; take care not to damage threads and wiring during removal. If engine fault light is on or fuel economy worsens, check this sensor first.