Okay guys I have a dilemma here I have a 96 F 150 4 .9 liter straight 6 I'm currently running too lean codes Bank 1 and Bank 2 I had these linkage when I bought the truck I rebuilt the motor including the intake exhaust gasket I smoked the vacuum lines and had no leaks and I'm still clueless as to where my lean codes are coming from I replace the fuel pressure regulator and the only way that I have passed emissions in illinois was by running a mixture of 93 and 100 octane to make 97 octane and that took away my lean codes any whelp or suggestions will be extremely appreciated