Since you have replaced the EGR, I'd be checking the wires... after all they are 20+ years old. Test continuity and look at the 5v reference voltage and good ground at the EGR. Same thing at the TPS. You might find that the connectors have migrated inside the plastic and are not making good contact with their matching parts on the TPS or EGR itselfr. Just a thought.
I don't have the codes memorized, nothing near, and wonder what they actually mean. If I remember, the EGR code means that it is not sending back the volts the ECM expects when the EGR is closed (or full open...). I think somewhere on this site there was talk of the volts not quite getting down to .2 or whatever, the the ECM expected for a closed EGR. I don't remember the fix....
tom