Ford P0155 OBD-II Trouble Code Definition: P0155 A/F Sensor 21 Heater System Malfunction P0155 Ford OBD-II Trouble CodeDescription: OBD Trouble Code P0155 O2 Sensor Heater Circuit What does the code mean? OBD-ii Code P0155 definition: This code definition:the front oxygen sensor on Bank 2. The heated circuit in the oxygen sensor decreases time needed to enter […]