If you pull a coil pack connector, the engine should drop revs and sound differently. If a cylinder doesn't respond, it wasn't firing.
You can pull your injector connectors (with the car off) and test the resistance of the terminals with a multimeter. 10-14 ohms is considered in spec. I'd do them all just to give you an overall picture.
Cleaning the injector & coil pack connectors with electrical cleaner and then coating them with dielectric grease is a good start before going on to other issues.
