Hi, today a dealer agreed to replace my GMC 2001 injectors ! I have 133k on truck ! They will begin tomorrow! I'm wondering if time has shown the new injectors to be a real improvement over the original's ! He also indicated the fuel filter needs replacing ! He said they only measured 5lb of pressure, so it must be plugged! Only has 9k on filter so I doubt it, its the new 2 micron filter! Hes doing injectors without fussing so I didnt want to beat on him about a filter and told him to go ahead! He could be right, also ! How is this fuel line pressure measured ? Did he get the number while reading the truck computer or put a guage in line somewhere for fuel pressure reading. Is the fuel pump in the tank ??? What should the correct pressure be ? I'm asking, because I want to ask him to recheck filter when all repairs are completed !!!! I want to be a bit knowledgeable when talking to service manager! Thanks for your help !!!!! Dan in sunny Minnesota !!!!