After the sceene when T3 burns the ass off HK you can go to HK and ask him about why is the navicomputer locked and HK says something about it but then when you talk to T3 nothing Does this locked navicomputer have anything to do with the planet that was cut by obsidian

From what I've heard, it's Kreia who locked down the navicomp and who tells the Exile this providing you have enough influence with her.

She told me, yes. Which surprised me, because I thought T3 had done this.