If the wires are original then yes change them for sure, made a world of difference on my '94 4.0l, I didn't even realize it was running that bad, lol.
I would look at plugs, if they look OK reuse them, but if you do decide to change them make sure to use motorcraft brand, for some reason these 4.0l ruin other brands, misfire like crazy.
I would also get a can of SeaFoam to add to the gas tank, about $10.
Fuel injectors fire at the same rate as spark plugs, so a lot, but they have moving parts and can get varnish build up, this can cause sticking and also dripping instead of spraying, gas treatment helps clean off the buildup, most Name Brand gas stations sell gas with cleaner already in it, but some only have it in the Premium grade.
Anyway the Seafoam won't hurt anything.
Running bad when cold or warm is a good lead, it means that only a few of the sensors could effect the engine or it is not a sensor at all, but another problem that a sensor is detecting and telling you via the CEL.