I have a 2002 Silverado with the 5.3 engine. I am getting terrible fuel mileage and the fuel system seems to be running rich. It is sluggish at low RPMs and runs like an older carbureted vehicle that is having a flooding issue. It also has the signs of running rich such as a black sooted tail pipe and black plugs. I have done a tune up on it but it hasn't helped. My check engine light is not on but I'm pulling an OBD code of P0002, fuel volume regulator control circuit range. I'm getting 4-5 mpg less than friends with the same truck and, at today's gas prices, I'm about ready to get rid of it. I'd prefer to fix it though as it would be much cheaper than buying a new truck. Can any of you guys give me some advice on what may be going on? Thanks