NEED HELP

I HAVE A CODE P0176 THAT COMES UP. W/ CHECK ENGINE LIGHT ON. THIS IS THE FUEL COMP SEN SOR. I ALREADY REPLACED THE O2 SENSORS, AIR INTAKE SENSOR, AIR FILTER, RAN DRY GAS AND OTHER FUEL PRODUCTS TO CLEANIT OUT, I EVEN CHECKED THE MAIL GROUND WIRE, BUT THE LIGHT KEEPS COMMING ON. I WENT ONLINE AND BOUGHT A BY PASS FOR THIS PROBLEM AND CLEARED THE CODES SEVERAL TIMES BUT THE CHECH ENGINE LIGHT STILL COMES ON. I CAN CLEAR THE CODE AND RUN THE TRUCK THE LIGHT WILL STAY OFF TILL I TURN THE TRUCK OFF. AS SOON AS I TURN IT ON THE LIGHT COMES BACK ON.