Alright so about 6 months ago I changed my plugs from the factory plantinum plugs to the copper plugs. Lastnight I changed them, again with copper plugs. I got in the car this morning to get some food and the car has a nasty hesitation/jerking upon takeoff and at speed. I mean it feels like I am towing a 40 foot boat behind the stang. I know it is a misfire, but how can I go about diagnosing the exact problem? There is no SES light being thrown, but I just need some guidance because this didn't happen when I changed them the first time. If anyone can throw some helpfull information my way it would be greatly appreciated.