i bought a long tube x pipe made by mac. my dad has a sweet lift so installation was a breeze, i did it myself. i can really feel a differencwe in power BUT IT SOUNDS LIKE ABSOLUT ISH i have flow master 40 on the car, and when i floor it all you hear is rattle. and its so bad i want to take the whole thing off. i know all parts are on in nice and snug so the only thing i can think off is the flowmasters, please help. oh yea i was told i had a good chance of getting a check engine light, the one ggod thing is i didnt get one

 

did you get long tube headers or an x pipe i couldnt really tell what you meant. Either way it sounds like you have a nice exhaust leak going on there. Get back under the car and make sure everything is tight fitting.

 

your very vauge, impossible to tell just by that, is it like a popping exhaust leaking sound? or a metal to metal sound, like a screw or bult was left in the pipes?

First check to see if your catback moved when you put on the X. the mufflers or pipes are prob hitting something under the car, like the 4 link, or the underside of the floor pans. check to see if you have ample clearence around everything.