So I drive a 2000 5.4L 2v Triton, so I have replaced the spark plugs and coils and I'm still having and issue with a misfire, the truck won't throw a code, but I had problems with cylinder 3, I have tried to diagnose the misfire by unplugging the coils but all it does is get worse when I unplug each coil?

Could be something internal? Plus my valve seals are going bad if that at all ties in with the situation

 

That will definitely cause a misfire.

 

On a second note gas smell in cab is commonly a loose plug symptom . Blackened porcelain or threads on plugs are blowby , which can burn a plug slap up in no time . All plugs need to be torqued 25 - 28 foot pounds, not by feel, they will back out .
Of course a system that is adding to much fuel because it thinks it has too much oxygen coming to o2 will throw gas out tailpipe , not sure you would smell it in the cab .
We need to see mode six report on each cly . But its hard when pcm is not finished testing or can finish complete .We need to see o2 graphing .
There is not a clear path to check at this point. Have you cleaned the tb and maf .

 

How do you know it's #3? Is it a dead steady misfire or just sporadic? Unplugging a coil creates a dead cylinder misfire which is worse than a sporadic misfire.

 

Have you checked injector(s) yet?