Let me give you a scenario of when I hear this problem the most. I'm driving around for like 25 minutes. I go down a hill...start to go up a hill, with my foot in the same position as going down, I head up the hill and feel a loss of power, and with that a clicking/stuttering sound..Rub your hand over your keyboard and picture it sounding kinda deeper than this..louder with more acceleration..I've added fuel additives..oil additives..new air filter..I'm thinking it could be the knock sensors..but I've also heard carbon buildup in the combustion chamber..Any advice would help.
Thanks

These might be your issues.

My old 98 Used to do something like that only without the loss of power. And it didn't do this all the time. At one point, it went almost 4 months without doing it and it came back. It would do it when I would make a quick launch reving in first or econd gear around 4000RPM. So I think it would of been the knock sensors in my case. And I sold the car so I can't give a solution.

As for you I think it might be a combination of both carbon and Knock sensors since you claim loss of power. What else? If this happens at idle also then you have bigger issues.

thanks for your advice.