its all good man, yes you would have to weld one side, because this goes in place of your stock cat, which you would have to cut out as well, i would just call muffler shops in your area and see if they will and how much they charge for this . It only cost me 50$ to have this removed and my stock cat but inSorry for the noob question, ive yet to have a chance to get under this car and see how the stock exhausts looks, so my questions is. Would you have to weld this part onto the stock exhaust? Or does it clamp in on one end and obviously bolt in on the other.