OKAY I AM NEW TO THE FORUM. I work for an electric company that beats the piss out of their trucks fyi. I currently have a 08 top-kick 5500 4x4 with issues. So it had a P0087 code for low rail press., so it went to the dealer and they changed the fuel filter,fprv,fuel tank lines. The truck was d-rating itself and having low power issues. So the dealer said it needed a CP3 because they were commanding 26106.7 psi and only getting 23931.2PSI which to me is with in spec. so they claim it idles just fine and you can drive it short trips and its fine but once it warms up and/or goes under a load the truck looses power and on goes the MIL lamp.. I don't believe it is a pump issue......if any one has any input i would appreciate it greatly as the dealer has us over 6 grand in this damn thing. Bal. rates are +-1.2, fuel tested at 37 API