running on 7 cylinders when warm

[blowincoal02]

Hi guys i have a new too me 2002 7.3 173,000 miles and yesterday it started running bad like missing allmost but no cel light .. and then it startes running on what seemed like 7 cylinders .. and i got home and let it cool all the way down and started it back up and it was running and idling great and once it got warmed up it started running on 7 cylinders again ... this is my first diesel truck and im just dumbfounded on working on it .. if someone could please help me i would greatly appreciate it ... iv only had this truck for a week and have no tools too check anything on it really ... it has a new fuel filter the day i got it and a fresh oil change and filter too.. only mods are afe stage 2 intake, 4" mbrp exhaust and an edge programmer .. that i will be removing when i get home cuz i dont like it at all