Weird Problem. V6 LS 2003 Silverado runs fine with full gas tank. However, when gas gets down to 1/2 tank, it starts to miss and hesitate upon acceleration from stop. Otherwise, runs fine. Replaced plugs with no help. My guess is the gas filter. Where is it located?

 

you might want to start logging the amount of fuel filled when refueling and miles driven. Sounds to me like the fuel level sending unit is not accurate. you may be burning through a full tank but the sending unit is reporting you have fuel.