Diesel Bombers - help with my 6.5td please

alright here goes guys got quite a bit. all start off by saying this is my first 6.5 but ive had other diesels before so i know a "little". well first off ive replaced the following compnents due to issues i was having. 1st lift pump to a 93 6.5 for more psi 2nd fuel filter 3rd glowplugs all 8 4th OPS 5th fuel relay. now after all that my truck now starts alot better and runs awesome but still have one issue and i cant figure it out so maybe you guys can help. driving down the interstate to work runs smooth lots of power and then boom it stall hard then refires right away then the service engine light illuminates and still drives fine and all power is there no smoke no stuttering just that one bang and then the light comes on. then the next day starts no problem idles great drives great then again on the interstate boom again and service light on again. guys im stracthing my head at this and dont know what else to do and really appreciate any and all help