Hi I have a 03 ford f150 4.2l it is a obd2 code po171 and po174

Question

I have a ford f150 with the 4.2L and it has a po171 and po147 I have replace the lower intake and the EGR val and in like 75 mil the light came back on

Answer 1

Hi there,

Check the fuel pressure next. If the fuel pressure is low then you will have the lean codes on both banks of the engine. Timing off could also cause this.