I have an 07 GMC Duramax 2500. It recently started going in limp mode and sets low fuel rail pressure code. The check engine light comes on and the change fuel filter light comes on. I have changed the fuel filter 6 times lately. Also I have Changed the fuel filter housing and the water in fuel sensor. I clear the light after I change the filter and it goes out for a few miles then back on. There are no modifications on it. Also when I change the fuel filter it is almost empty. If I bleed the system out every time this happens it lasts for a few miles and then back to limp mode again! I do not have a ppe fuel pressure tester to test the fuel pressure yet. I was kinda wondering if anyone else has this problem?? Thanks!