1997 Chevy Blazer misfire code

I have a 97 blazer s-10. I recently had it checked out at autozone with their computer anylizer that gives you codes for the service engine light and it said that there is a mis fire. I recently changed the spark plugs not even a year ago and the wire s are tight on the plugs, is there any other advice you can give me on wht else I may be able to check to find out what I have to fix or replace.
Thank you