My suggestion is , tighten your intake manifold bolts. They are only bolted down to 105 inch lbs. Which is not alot. Beware you can easily strip the threads as you are tighten in plastic.
My 11 was bouncing In idle speed, I finally found it when I was looking for a vacuum leak.
Easy test, spray your intake with wd40 where it bolts down If it changes idle, you have found. If no, it's something else.
My 14 did this as well but it has a supercharger installed on the and it was the 02 sensors in front of the cats.
It can be different problems