I think since the ss/sc's have coil overplug ignition, a bad spark plug would set a code speific to a cylinder. like a p0301 p0302 ect. but i have seen p0300s set by bad plugs as well. it could also be an injector, coil, or a wiring fault.
do you notice anything else thats different about the car now? like say, does it take longer to start it, is the cel on?