So I got Sonic 2006 to almost work

Title says it all, if someone knows how to fix Cell Synch Error Busy, boom, we will have another playable game on RPCS3.

are you using Zangetsu build?

Yeah why?

Well, there's your problem. You're using his build.
His build is probably less accurate then without his changes. I mean he literally disables PPU opcodes to get game(s) working. It's already noted in reporting guidelines, that you should only report when using the master build. Anyone else's build and it will simply be discarded as useless.