Toyota Corolla Rear Oxygen Sensor 89465-12700, Air-Fuel Ratio Sensor Upgrade for Stable Emissions

When your Toyota Corolla shows check engine light, elevated fuel consumption, or exhaust emissions exceed standards, typically the downstream oxygen sensor (air-fuel ratio sensor) has aged or failed. This sensor monitors exhaust oxygen and feeds signal to ECU to adjust air-fuel ratio for combustion efficiency and emissions. OEM number 89465-12700 (compatible with 89465-12620, 89465-12640), fitting various Toyota Corolla models. Install only after engine cools to avoid burns; use a special oxygen sensor socket and observe thread direction; after installation clear fault codes and road test.