What can cause a cylinder 3 misfire in a 1996 Saturn SC2?

Take a compression test of that cylinder. If it is low. it probaqbly is a burned valve, If it is ok, check for a bad injector if it is port injection. Also check for a vacuun leak. Change your spark plugs and wires.Also Check for broken Sparkplug or bad wire...I had Identical problem when I bought my 01 Nissan and it had water in the plug hole from being detailed,I sprayed penatrant oil in hole and on plug wire and problem solved within 1/2 mile.Also check for oil in the plug holes ...Most likely cause is a burnt exhaust valve BUt yes do check basics first A commoc problem is corrosion on the ignition coil especially #3 coil tower Remove the wire from the coil and make sure it's not corroded. CHeck the resistance of the wires and check the plug gap