I have a skip on the motor, I hooked up the car onto the computer and it said cylinder No.6 was misfireing. I replaced the coil, then it went onto random misfire. I replaced all the coils and it still has the skip. I had replace the plugs in the spring. Could it be possible that I have fouled a plug?

 

Basically what I would do and have done was :
1.) switch coil with another cylinder or completely replace ( which you have done .
2.) change plugs and make sure they are gapped correctly if your motor is stock gap from 41-44
3.) check your valve cover for leaks ( pull the plug and check for oil).
4.) could be a semi clogged fuel injector .
With that being said I did all of those and my missfire is gone .
I replaced coil , changed all plugs and valve cover due to a small leak and was still getting a missfire . I the. Changed the fuel injector ( 97,xxx mile car) and bam gone and runs flawlessly .
That being said take those steps and you should find out what's wrong .
Def pull the plug though and check it , that's just obvious though . Let us know what happens