I recently upgraded my phone from a SGS2 i777 to the SGS4 i337. Of course after years of custom ROMs and kernels on the S2 I wanted to do the same on the S4. I attempted to perform the hack associated with the Loki exploit while running stock Mk2. After trying several methods and receiving the failure to root message I gave up and decided stock wasn't that bad and I could make do. I noticed that even after these attempts failed either Super User or Super sure would be installed. Sadly the super su binary needed to be updated but it never actually updated. I also noticed that I was getting the custom boot screen but no real root. Anyway I looked around the Web and xda for a solution, either a way to gain full root or to reset back to full stock. I was interested in trying some of samsung's apps as well as At&t's Isis wallet so I decided to try to unroot and "play by the rules" for a little while before I started using custom roms. I read in several places that a firmware update removes root (as well as patches the exploit) but I decided it was the easiest way to "unroot" because I didn't have any root privileges which of course were needed to unroot if I used any guide online. After an ota update from 4.2.2 MK2 firmware to 4.4 NB1 is still have the custom boot screen and Is is still things my phone is rooted and therefore will not run. Some how I have enough root to trip the custom screen and stop Isis but not enough root to unroot. Does anyone have a solution to bring my phone back to full stock without root in such a way that I don't lose or can reinstall samsung's app and a few if At&t's ? All relatively safe suggestions welcome. Thanks for taking the time to read and any help.