I can finally update this thread as my car should be fixed now, had to go back and forth from my tuner a few times. These info have bee backed up by UpRev and hopefully I'm reporting them correctly, I apologize in advance I'm gonna say some BS.
- Apparently there is is a so called 'cold map' that the 2013, once flashed, fell back to and for some reason the ECU wasn't going back to the tuned map. I believe the cold map had a stock-ish configuration, hence the lack of power. Lack of power in my case comes without a proper tune because of my mods. So the solution was to literally copy/paste the tuned map over the cold map. Now the car seems to behave like it should.
- Also, always the 2013 seems to try to run A/F mix as lean as possible (even stock) and installing HFC translates into having a CEL. We disabled it but this info needs more backed info, so take it as it is as I don't really have more info. I am planning to message Fast Intentions and ask if they've heard about 2013s having CEL with their HFC/TP products. I am maybe thinking of setting up A/F monitoring though as this leanness kinda freaks me out. I'll probably be looking in what the market offers as of gauging...
I think that's it for now, I'll update this if I have more info/corrections to do.