Originally Posted by 01jeepgrand
sorry, it is the v6 4.0 liter
Ok. Just to let you know though, the 4.0L engine is not a V6, it is an I6, which just means it is an inline six-cylinder engine... all the cylinders are in a row, not three on each side like a V6 would have. No worries though, even those that might know it is an inline-six cylinder engine still often just call it a V6 out of habit.
The spark plugs are underneath a plastic cover that covers the ignition coils and plugs for that engine. They are on the passenger-side of the engine block and are pretty easily changed once you get the plastic cover removed. Take a look, you should find that they're fairly easily changed.
Avoid gimmick plugs like Splitfire and Bosch Plus2 and Plus4 plugs, they just don't work well in that engine. Stay with good quality plugs like Autolite, NGK, Champion, etc. and you'll be fine. Gap them to .035 if they're not pre-gapped which most are now.