Waternooze14

I have a 2012 Se with 3.0. I have a misfire in cylinder 5 and getting a p0305 code. I checked the coil and was ok. Pulled plug and it was covered in black soot. Leads me to believe I have a bad coil with not enough spark or a leaking injector. I swapped #4 and #5 coil to see if code moved and it did not. I removed intake to remove injectors and after looking things over realized all the injectors and coils are the originals. ( I am 2nd owner and the car does have 170k on it) Well I decide to replace all injectors since Im there and there pretty cheap and all the plugs and coils as well. Put it back together and I still have a misfire in #5. So I send the pcm off to be checked and it is working just fine I am told. I am at a stand still with this car. Anybody have any other ideas that I can test for to try and find my problem. Thanks