1999 Ford Ranger Codes P0171 P0174 P0306

Question

>how to repair codes po0171/0174/0306

Answer 1

HI there,

The P0171 and 174 codes indicate there is a lean fuel mixture on both banks. This could cause the misfire on cylinder 6 which is the P0306 code.

Usually when you have a lean fuel mixture on both banks it's due to low fuel pressure or a bad mass air flow sensor. I would start by solving the lean mixture issue and then see if the misfire code comes back or not.