1989 2.8 Corsica stalls\misses when i try driving 65-70. Sometimes makes a sound(possibly backfire but I'm really not sure) it doesn't do it ever when idling as long as u stay below 65... Needing to figure out if this is engine problem or if it can be fixed or is causing damage.. Please help..

 

Not familiar with the car really. But if your converter is getting plugged up it can hurt driving at that speed and when your EGR opens it might fill your intake with exhaust gasses. Try unplugging the EGR plug or vacuum line, whichever it has.