Why can't I install firmware?

[AC Question]

why cant i install firmware

Ok. I have an i337 and I did the update that everyone says not to then tried to install a custom recovery that made my boot loader locked down ..it gave the message unauthorized software detected when I would try.. so I was stuck with odin tryin to flash original firmware.. no luck ..would stop at aboot.mbn nand fail...so I played around and removed the abbot.mbn file and it tries now to install the system ..gets to the end and fails.. I have flashed a 16gb pit file with the tar still no luck ive erased the nand also..everything ive tried fails..im on KOT49H.I337UCUFMLD.. I know this because .. I also flashed a 32 gb pit file and tried to enter my boot loader.. and now my knox is still set to one but the 32 gb pit file did something and I have stock recovery back and can access it every time even after I reflashed my 16gb pitfile.. so what is my next step I know I have no system installed..but how do I install a system on it now I have both stock recovery and download mode but nothing works...