Engine revving up and down violently (for the first few minutes of driving)

Hi there, my car listed above is SI model. After it starts the engine feels like someone is stepping on and off the gas over and over at every RPM. After driving for a few minutes the engine will go back to normal. I have no idea what is causing this. Any help would be greatly appreciated. My only mods that I installed four years ago are: Injen cold air intake, Skunk 2 alpha race header, full Race full exhaust Flashpro - Vitviper tune (at the moment it is stock, it behaves the same with or without the tune.) Here is a video, revving starts after a few seconds https://www.youtube.com/watch?v=FLwyqV9M--w

In the video I start trying to hold the rpm at 2,000 and then 3,000. It continues to jump plus or minus 500 RPM even when I am not moving the throttle.