P0304 code - cylinder 4 misfire? on 2010 Chevrolet Equinox

I switched coil pack and that did not correct it I also put a new spark plug in it, even though I put 4 new ones in back in May, and that did not correct the problem. Can some one give me some help on what might be causing this code? The engine is skipping a small amount(not bad) at idle. Thanks very much in advance.

4 answers 1 comment
Do a compression test, and/or injector test. Test power ground signal at connector at coil.
Thanks very much for your help. I will attempt to get that done tomorrow.
agree with #1
Also check for a vacuum leak near #4
poss injector or wiring at inj or coil pak