Not sure if your pump relay has a feedback to the computer, but a primary circuit failure is something on the input side, not output to the pumps, I would think - especially if your pumps are running when they should. The box it's located in is a black box with relays and fuses in it on the inside of the fender, IIRC. If you have dual pumps (in tank and out of tank), I would think you also have two filters, one low-pressure, one high-pressure. I'm going to take a guess that the relay is not feedbacking to the computer telling it that the pumps are running - which may or may not affect injector firing, etc. 45-50 PSI should be enough - what do the specs say, or do you have a book? Did you notice any wetness in the vacuum line going to the FPR and a gas smell (would indicate a bad FPR)? What does the output of the 'coffee can' feed? A screwy MAP sensor or vacuum input to it or bad electrical connection from it will cause issues similar to this as well. The EGR issue will also contribute to this. Some of those may be operator-error related during diagnostics, but you may want to check some of the connections to things (i.e. Knock Sensor). Best bet is to eliminate the error codes one at a time until you have cleared them all.