Cadillac Repair: Drivability, vacuum leaks, fuel filter

Question
I have a 1996 sedan deville, and i keep getting a code for multiple cylinder missfire. Ive changed the plugs,wires fuel filter, and the code keeps comming back.Also on excelleration it stumbles, surges, and sometimes backfires through the air intake, im thinking the egr could be bad but its electronic. How can i test it. the car has 130000 miles on it. Can you give me any tips as to what i can check?? there doesnt seem to be any vacuum leaks

Answer
What code or codes are you getting and are they CURRENT or HISTORY codes.

As the codes display when you use the OFF and WARMER buttons as each code displays it also states whether the code is a CURRENT or HISTORY code.

Run the codes again and let me know.