2005 Ford F150 4.2 V6 sets P0171 code only.. LTFT B1 reads 29.7 and never changes with rpm's LTFT B2 reads 3.5 + or - and fluctuates with rpm;s
FTST B1 READS 5.97
FTST B2 READS 8.22
O2S BANK 1 SENSOR 1 VOLTAGE READS .10
O2S BANK 2 SENSOR 1 VOLTAGE READS .07

Cleaned Maf sensor, checked for intake and exhaust leaks, changed pcv and checked fittings.
Truck has slight miss and hesitation but only sets P0171

 

This is the 97-03 forum, you'll probably get more help in the 04+ section

 

Thanks