Your fuel to air ratio is not right. It could be a number of different fixes.
Bank 2 running too lean.
P0171 System too Lean (Bank 1)
A lean mixture is referring to the gas/air ratio. Lean being less gas
Your system is too lean. That's what it will say on obd2 scaner tool. It means that your air to fuel ratio is too lean.
1999 Ford Taurus. System Adaptive fuel too lean banks 1 and 2. How can I fix these.
Too lean of a mixture. See if a jet is not clogged and clean the carb.
POST CATALYST FUEL TRIM SYS TOO LEAN BANK2
Your gas/air mixture is too lean. Adjust your carb to be more rich.
Trouble code P0174 means:System too lean (Bank 2)
to lean = nish'an (נשען)
An engine runs by the combustion of a mixture of oxygen and gasoline. If this mix has too much oxygen, it is said to run lean. When the mixture has too much gasoline in relation to oxygen, it is running rich.
the gas mixture is 32.1 ratio if you put too much it will be too rich and cause plug fouling if you dont put enough it will be too lean and blow the top end so mix it 32.1 ratio with 2 gallons of gas and it should run like a dream