Is there a fix to a bad gas gauge?

most likely it's not the gauge!usually when this happens,it's the sender on the fuel pump module assembly has/is failing.it is the float/switch that fails,not the pump.but to correct the problem the entire fuel pump module assembly has to be replaced to correct it.and yes,it's all in the fuel tank.the bed will have to be removed or tank has to be dropped.rather than spending over $500.00 if you do it your self,you could keep the tank full or keep up with the miles you get per tank full with the odometer trip button.should not have to do that on a 4 year old truck,good luck with the NHTSA!