MY 08 GT HAS A HESITATION,ALMOST BACK FIRE, AT 4,000 RPM'S AND ABOVE....I SUSPECT IT MAY BE FAULTY PLUGS OR INJECTORS....I WENT TO THE DEALERSHIP, SINCE IT IS UNDER WARRANTY, AND THEY COULDN'T FIND ANY DIAGNOSTIC CODES;HOWEVER, THEY GOT APPROVAL TO CHANGE THE PLUGS....WHAT IS CAUSING THIS? I ONLY HAVE 1000 MILES ON THE MOTOR, AND IT IS A DAILY DRIVER....ANYONE HAVE/HAD THIS PROBLEM BEFORE? I WOULD GREATLY APPRECIATE YOUR ADVICE!

THANKS

 

If you got approval to change the plugs have they been changed yet or did they get swapped out and you are still having the problem? I have heard a few incidents where people have had faulty plugs. Usually most cars will throw a code when this happens. If the plugs haven't been changed at this point I would definetly do that and then go from there.

 

they haven't been changed yet.they had to order them...yes. ford had to order them!

 

They are doing it under warranty? Even though you were the one who added octane booster to your tank? Doesn't sound right to me.