First, I'd check fuses and tail lights. Belaive it or not, if you have a burnt out tail light, cruise will not work. Then relays. As for the sputter, I'd do plugs and wires first and if that doesn't solve the problem, move on to the coil packs. When mine did that, I had the dealer scan mine and found out my 3,6 pack was gone. Hope this helps some.