Klotz

My ws6 has been bucking at 50% - WOT in mostly 3rd gear through 6th but occasionally happens at any gear. This mostly happens in higher RPMs but can happen any any RPM as well. This has been happening for about two weeks. It seems like it came out of nowhere and I'm thinking the problem is detonation from carbon buildup. The car had a plugged cat and after that was taken out it ran great for about a month until this happened. I'm trying to figure out what it could be, i ruled out a few things already. So far I cleaned my MAF, tried another MAF that's known to work, changed the TPS, changed the fuel filter, put 1/4 can of seafoam in the vacuum line and another 1/4 in the gas tank. I don't have any diagnostic software or anything which makes it harder to diagnose. There's also a ticking noise that appears to be coming from the bottom end... You can hear it at the very end of this video.