It started breaking up and popping through the exhaust only under load and WOT ..

It was 100% fine then i tried to pass somone i heard pop pop pop after it was at full boost. It does it with the stock tune and bolth tunes 1 and 2 uugghh Ive had plates on it for 5 hours! So I have to call the dealer in an AM. it wasnt a ford dealer just somt performance car dealer and im real nervous at the moment. I mean it breaks up BAD under wot but if u go to about 80% throttle its fine