EGR Differental Pressure Srnsor

[JCTL Jamie]

I wondered if someone could point me in the correct direction. I got a code several weeks ago regarding the differential pressure sensor which I replaced as well as the wiring harness however I still have the code. If you do not know I rebuilt this engine a couple months back and all was good up until a few weeks ago with this code I'm not sure what else could be the culprit any suggestions would be much appreciated

Thanks