1st comment: it appears that you've mixed up the KOEO and CM codes (KOEO codes come out first).
Code analysis:
KOEO 67: Can I assume he has a manual transmission? KOEO 67 is almost always from running the KOEO test with a manual transmission in gear. The computer expects to see the transmission in N. If this is an auto tranny (KOER 65 suggests it might have an E4OD with an o/d cancel switch), there could be a fault in the Park/Neutral position switch. Should be easy enough to track down with a wiring diagram and a voltmeter.
KOEO 95: Indicates a fault in the fuel pump circuit, and you indicate that the fuel pump doesn't seem to be working right. Time to get out a wiring diagram and a voltmeter and determine what problem the fuel pump circuit is having.
CM 87/95/96: All point to fuel pump circuit problems. At this point I'd ignore these codes until you resolve the KOEO 95.
CM 31/41: CM 41 could be related to the fuel pump problem (fuel pump not pumping means engine runs lean). CM 31 may be its own problem, but focus on the KOEO codes first and we may return to this one later.
KOER 21: ECT out of range. Often (especially when there isn't a CM code to go with it) this code is triggered by running the KOER test on a cold/cool engine. Make sure engine is at operating temperature before performing KOER test.
KOER 74: BOO circuit. Almost always, this code indicates that the operator neglected to press the brake after engine id was output. Repeat test and make sure to press the brake.
KOER 65: I don't have a code list for a '93 7.5, but my generic code list suggests that this might be another operator error. If it's an E4OD tranny, the PCM might expect you to press the OD cancel switch. If this code doesn't make sense, we might need to find a code list that is year/engine specific.
So, the main thing to work on at this point is the fuel pump circuit.
