Hey guys need a little help seems the better half thru the box and paperwork to my tuner away. The two codes jsut popped up last night when coming home and it felt like bad gas or a fuel filter problem going up a steep grade would just surging back and forth and if you tried to give it gas it would die pull over fires right back up and away you go for a ways and it does it again found po174 need po191 now and where is the fule filter on these trucks 2004 5.4 supercrew 4x4 Thanks

 

po174 = Sys too lean (bank 2)

po191 = Fuel Rail Pres Sens Circ Range/Perf