I have a 04 w/ 4.6 4x4 XLT. It has begun running extremely rough at idle and while driving. It acts like it is misfiring. While accelerating the whole truck shakes and sounds horrible. The first code it threw was P0171 (lean bank 1). Made some repairs, still had the same issue, however its now throwing a P0174 (lean bank 2) code.

The following repairs have been completed with no luck fixing the issue:

All coil packs replaced
All spark plugs replaced
Mass Air Flow Sensor cleaned
Throttle Body cleaned
New PCV valve
Fuel Filter replaced
Air filter cleaned
checked for vacuum leaks
use Lucas fuel treatment regularly

Starting to run out of options and ideas. Just looking for some advice and a direction to follow. Thanks!