Intermittent rough idle?

So this car starts fine from cold. About 3 minutes later after the idle/rpm settles it starts to idle up and down. Rev it high about 2000 for a bit then leave it and it smooths out. A bit later it does the same thing. It didn't have a check engine light so I replaced coils, plugs and PCV as I had an extra set knowing this is the most common with these cars. Oil is full same for coolant. But there is also water coming out of the tail pipe with black material. I have seen several cars do that before. Its super cold today abd car is inside the garage. You drive it and it's fine, no misfires at all. But leave it and in a bit it does the same thing. Took a screen shot of all the codes that were there even though check engine light and epc were not on. Deleted them and only the misfires came back so far. Also took screen shot of some live data in case you may spot something out of the ordinary. I have 3 videos attached too. I have an idea of what it could be but I want to hear your thoughts. I will also do a smoke test to eliminate that possibility. Thanks