Rough idle, Slight Misfire with no codes

[mill]

Hey y’all! I’ve got a 2008 ram 1500 with a 3.7L. I had noticed that he was idling rough and I was feeling a slight miss but I didn’t have any engine codes and the misfire monitor was ready. I was able to hook up a scanner and see that cylinder 4 was missing about 18 times per 200 revolutions.
I replaced the plugs and coils and ran an intake cleaner. Had a lot of crap blow out the tail pipe and he ran like a dream for 2 days with no miss before I started feeling the miss again. Same cylinder but less frequent.
If anyone else has dealt with something similar I’d appreciate any input you may have

 

[Dodge 1500 4X4]

I would swap #4 fuel injector W #5 injector and see if the misfire goes to #5, do a compression test on #4, any ticking going on? Maybe valve spring.