Hello folks I have an ongoing power issue with my truck ever since i bought it. Not real familiar with common rails as of yet. Seems to have low power compared to other trucks of same statue that i have drove. Codes that i get are P0251 and P0541. Truck will stumble going down the road occasionally not everyday. When i say stumble it feels like you turn switch off and back on. Tried a pressure box on it can't really tell no difference at all in performance. Fuel psi is 7-8 reading at cp3. From what i have read sounds like it very well could be the pressure relief valve?? I haven't went and dropped the $$ for a rail gauge yet. If this sounds like the problem comments on places of purchase would be appreciated. . Honestly i would carry it somewhere to have the pressures checked but around my area i don't feel as the dealerships are helpful or smart enough to be of service on this issue. . I maybe bad wrong though. But thanks for all the help in advance. . Tired of sick truck. .