Hyundai Repair: Check Engine light 2001 Accent, hyundai accent, dealer charges

Question
2001 Hyundai Accent 65000 miles:  For several months the engine will "miss" on occasion - about once a week under a load, but very inconsistent.  Today the "check engine" light came on, and it's running extremely rough, almost like a cylinder is not firing.  If there is a non-firing plug, will it be oily when I take it out?  What else might this be?  o/2 sensor?  Plug wire?  What do you think about the Autozone computer check to diagnose the problem to save the $$ the dealer charges?

Thanks

Answer
Fisrt thing i would say it i think  it is a plug or wire but i would also say do a compresion test an leak down to make usre thats all an i would say at that milage a complete tnue up from plug filetrs an all, with the other an also a furl presure test this should get you the reponse you need in it,an there test will tell you the same thing that the deal does.