I recently had a 51 gallon Titan fuel tank installed im my PSD. Nearly doubled my capacity! It all looked good until about a week later when the truck popped up a P code for the PCM. Had that re-flashed at a dealer. Came back within a few days. Had the installer check it out, sender is at specs and even reset the Puter, but ?? Now I get the Low Fuel warning, bottomed out gauge and engine light... Darn gauge won't go down... Any suggestions?

 

wire came loose or sensor failed thats what it sounds like to me