Oil on the plugs could also be from simply over-filling your oil. So you might want to check your oil level...when I got mine the dealership had way overfilled it, by at least 2 quarts and oil got up onto my #6 plug and caused misfiring. I changed all the plugs and drained out around 2 quarts of oil and it has been running perfect ever since.

 

Must you change the plug once it gets oil on it? Won't it just burn off?

 

no you don't have to, just clean it up real good

 

Can you have this same problem without having the CEL come on?

My '01 does the same as joshafmil's.