You will need a 3/8 extension , 3/8 ratchet, 5/8 spark plug socket and 10mm, 12 mm sockets, and a feeler blade to set the plug gap to .039" to .044" plug gap.
On the 2.7L V the ignition coil pack is on the side of the cylinder head, remove the plastic trim cover over the front of the engine, remove the plug wires and replace the spark plugs one at a time so as not to mix up the firing order. Labor time shown to replace the spark plugs is 2.7 hours so that implies the intake plenum will have to be removed to gain access to the spark plugs on the rear bank of cylinders.
On the 3.5 liter V6 the ignition uses coil over plug ignition and again the front bank of cylinders are easy to change the rear requires removing the intake plenum to replace the rear spark plugs.
Check out this free Hyundai factory website it has the information you need to remove the intake plenum.
...months ago. As a way of eliminating improper comubstion, we were thinking of changing out the spark plugs and wires. Mileage is 73,000, as we are getting about 19,20mpg on the hgwy. It used to be bett...