I have a 2005 Mustang GT and I've had a sputtering and exhaust pop issue since November. I had a hole in one of bafflers in my muffler so I got news one to see if that was the issue, but it didn't fix it. after replacing the mufflers I got thinking that the problem could be that my car isn't tuned for the weather being that it is a Florida car currently in north Ohio. since the weather has warmed up the car still sputters. my next thought was that it could have been the spark plugs since they were probably the original ones and the car has 102k miles. after changing out the spark plugs the sputtering got a lot better but under load it will still sputter and the popping is just as bad. Does anyone have any ideas on what could be the problem.