P0171 Ford - 1998 bank one lean code all sensors have been replaced but still have rough idle.

Question

all four 02 sensors have been replaced, IAC cleaned and installed new gasket, MAS cleaned, still have rough idle.

Answer 1

Hi there,

Try checking for vacuum leaks. At idle, spray some carb cleaner along the intake and other vacuum lines. If the trucks idle smooths out or increases then you have a vacuum leak.