Fuel system

Excessive depletion of the fuel mixture (P0171)

The PCM controls the value of short-term adjustment of the fuel supply (SHRTFT) and long-term fuel supply adjustment (LONGFT) in the regulation of the fuel supply in a closed circuit. If the fuel supply adjustment exceeds pre-programmed value, the PCM determines that the fuel mixture is too lean.

Excessive enrichment of the fuel mixture (P0172)

The PCM controls the value of short-term adjustment of the fuel supply (SHRTFT) and long-term fuel supply adjustment (LONGFT) in the regulation of the fuel supply in a closed circuit. If the fuel supply adjustment exceeds pre-programmed value, the PCM determines that the fuel mixture is too rich.