Oxygen Sensor

A4-A (Air Fuel Ratio Sensor (Bank 1 Sensor 1)):

A4-B (Air Fuel Ratio Sensor (Bank 1 Sensor 1)):

A5 (Air Fuel Ratio Sensor (Bank 2 Sensor 1)):

H3 (Heated Oxygen Sensor (Bank 1 Sensor 2)):

H4 (Heated Oxygen Sensor (Bank 2 Sensor 2)):