Tag Archives: Lean Codes P0171

When an engine mixes the air and fuel needed for combustion, there is a chance that the mixture has too much air. When that happens, the mixture is called lean mixture and the powertrain control module (PCM) will set fault codes. In Ford vehicles, there are two codes for this occurrence, which are Ford P0171 for cylinder bank 1, and P0174 for cylinder bank 2. A code reader or scan tool can be connected into the vehicle diagnostic connector. When …