Exhaust Question

Hey can anybody tell me if anyone has heard of taking out a u joint in hte mufflers of 98 monties it supposed to be after the cat and it is i U joint kinda bend in the exhaust .IF any one has done this can you please tell me how much it was and how efficent in creating alittle more horse under hte hood if it dose so at all thanks

1 extra 15-20 hp + sound

2 not worth it- you have to cut your muffler, better just go and buy something bigger if it fits