Currently driving a 1995 F150 XLT 5.8 L Truck. I'm getting really bad Fuel mileage and Starts up little rough at first then seems to run better after running a bit. Also I can smell raw fuel from tail pipe. Is this a fuel filter Problem? Truck has Dual tanks might it be a Fuel Pumps Problem?

Truck has a Slip in K&N air filter. Put in a New O2 sensor. Truck has a Hyper Tech Chip and seem to run real good for the first 5 0r 6 months and now gas Mileage has gotten bad. I understand from some other post that this model Truck has no MAF Sensor so oil from K&N Filter is not the issue.

I'm Mechanically inclined, but not Tech Knowledgeable........ Any help?