bad clunking sound when ICE turns on under low to moderate acceleration

Hey everyone,
I've owned my prius for about 5-6 years now and haven't really had a single problem with it until now. Under low to moderate acceleration it makes a sort of repetitive clunking sound and can feel the clunk as well. It goes away in high rpm and electric only.

I headed to the forums and google and everything pointed towards EGR, so I took that whole thing apart, cleaned everything like all the videos showed. Got the cooler, pipe, valve, and intake all cleaned up but they weren't really that bad like all the videos showed. I could still blow through them perfectly fine. Replaced the PCV valve recently as well. Didn't change at all.

So now I'm leaning towards a transmission problem, maybe just low on fluid? or the damper plate between the engine and transmission. Any ideas on what else it could be? Or anyway to inspect those parts to see if it's the problem? I heard there may be an inspection port for the damper plate?

The only code it's throwing, is the P2195 which has been on and off for th entire time I've owned it. Replaced the o2 sensor and didn't really change anything.

Any help would be appreciated.