Ford P0171 OBD-II Trouble Code Definition: P0171 Fuel Trim System Lean Bank 1 P0171 Ford OBD-II Trouble CodeDescription: OBD Trouble Code P0171 System Too Lean What does the code mean? OBD-ii Code P0171 definition: Basically this means that an oxygen sensor in bank 1 detected a lean condition (too much oxygen in the exhaust). On V6/V8/V10 […]