Just wanted to give an update on my issue. Found a couple issues that I was able to resolve. The EGR solenoid was not functioning found the ground was bad. fixed that and now it works. I also discovered, after checking my fuel pressure, that I didnt adjust it after I put a new regulator in and it was too high. I still have the issue with too high of NOX during the 25mph test, Not sure where to go now. Could it be excess carbon buildup?