Originally Posted by biker328
Its a 2002 wrangler sport with the 4L straight 6
Good, that it's a 2002 reduces what you need so far as the tuneup is concerned. For the tune-up part, you only need spark plugs as there are no ignition wires, distributor, distributor cap, etc. However, 2000 and newer 4.0L engines are DIS (distributorless ignition system) type engines so they are very picky about the spark plugs they run on. So be wary to not just buy any plug that is shown as compatible because not all truly are, at least not for very long. Avoid ANY single-tipped platinum plugs (platinum on just one side of the gap) like the Autolite AP985 or Champion 3034. Instead, the good safe plugs include the Autolite APP985 or Champion 7034 (double-tipped platinum) or Autolite's XP-985 which is iridium tipped. Any of those three will last 100K miles (really) as opposed to 15-25K miles with conventional plugs.
Good suggestions above for a coolant flush and new air filter. Avoid going with a K&N and stay with a good paper element air filter like from AC-Delco, Purolator, etc.