Pep Boys sucks a$$. A tune up is nothing more than new plugs, plug wires and a cap and rotor. If you pay more than $100 for the parts, then you are getting ripped off. I just checked Checker Auto for the necessary parts for a tune up on your jeep and the parts cost less than $90.Auto lite platinum plugs-about $3 each New cap-about $20 rotor-about $15 on the high side, can get one for only $6 plug wires- $30-$35 for a good set of Auto lite wires.hey will try to sell you the most expensive plugs since your a Cherokee it sure come with an inline 6, so 6 plugs at the amount of $6.99 a piece= to $41.94 that totaling up to $176.94 now you have to include tax depend what how much your state tax is. that will be aroung that price $185-$250.