Ford F-150 (2004-2008) :: Gas Fumes Smell When Let Off The Accelerator

I have an '04 f150 4x4 5.4L lariat new body style, I purchased it a few months ago. (I had an '03 f150 4x4 5.4L lariat that I am comparing the new one to) It seems like this 04 doesnt want to get up and go,(like the '03 did) best way to describe it is like having a potato stuck in the tail pipe. then after driving it for a few weeks I got CEL I think it was P0140, the day I was going to change bank 1&2 sensors 2, the code went away. So I didn't change them.

I instead opted to change the plugs (all plugs came out fine) now I notice a fuel smell when I let off the accelerator,(not sure if I smelled it before) its like a boat exhaust smell- not a raw fuel smell. I am wondering if all these things add up to a clogged or partially clogged cat or just a bad o2 sensor, I dont to spent $100+ for the rear two o2 sensors and still have the same problems, nor do I want to replace the cats and find out it was the o2 sensors all along. when I smell it in the cab, I do not smell it anywhere else, like: under the hood, or any where else under the truck, nor do I see a leak under the truck.