Cadillac: 1982 Seville 4100 EFI, sense car, nothing makes sense


Question
With a fresh tune up the car started acting crazy.  Boggs down, cuts off, spits back throught the carb, acts like the timing is off.
This started on a trip to Nashville from upstate SC.  Made it through the mountains with no problem.  Got to Sevierville, TN and it went nuts.  I had had no problems until three weeks before the trip so I gave it a complete tune up.  EGR, Rotor, Plugs, Wires, and a new coil pack.  I just changed the computer also thinking it might be the ECM.
When it gets hot and after I start it up and run it again for a while it will do this.  No leaks of any kind. Nothing makes sense.  Car is original with only 47K miles.  I am second owner.

Answer
Check for computer codes via:

1. Ignition ON.

2. Simultaneously push and hold the OFF and WARMER buttons for 3 seconds and release them. Diagnostic codes may appear as E43 or E76 or any letter/number combination.

Tell me how mant times each identical letter/number code appaers.

turn OFF ignition.