Our car was began to run rough and I was told to have it tuned and replace the spark plug wires. I did and the car ran great. Then one day it began running rough again and I was told it was a ignition coil pack (1 of 3). I replaced it and it still runs rough; like its running on 4 or 5 cylinders instead of 6. It has 127,000 miles on it. Since our budget is very limited, I thought I would go online and ask you. What do I do?