Code 303

[557SCJ]

Hello my cel came on the other day and my dad hooked it up to a snap on scanner and it thew a code 303? something about a #3cylinder misfire. What exactly does that mean is it something with a bad plug or something else? Also where is the number #3 cylinder on a 1997 ranger 4.0?

Thanks

 

[557SCJ]

Well i pulled the plug on #3 cylinder just now and its pretty nasty. Should I replace all plugs or jsut that one? It never has seemed to run really well since i bought it last spring but it does ahve 195000 miles lol.