i have a 96 f150 4.9L i keep popping the p0171 & p0174 codes so far ive done
intake/exhaust gasket, upper intake gasket, new 02 sensors, throttle body gasket, cleaned maf sensor, replaced egr and dpfe sensor, smoked the motor and no leaks. Im completely out of ideas as to what it could be I look at the live data on my scanner and no idle dissruption when i spray the motor with carb clean and the long term full is always at .20 or higher never in the negative what can i do

 

I'd test the fuel pressure and run some Techron in the gas.