Volvo S40 P0 172 system is too thick.

The long-term fuel adjustment value is obtained from the short-term fuel adjustment value and represents the long-term correction value of fuel deviation. If the long-term fuel adjustment shows 0%, it means that the fuel supply is just right in order to maintain the air-fuel ratio controlled by PCM; If the long-term fuel adjustment shows a negative value below 0%, it means that the mixture is too rich and the fuel injection quantity is decreasing; If the long-term fuel adjustment shows a positive value higher than 0%, it indicates that the mixture is too lean.