Hey guys I posted this ? In another forum but got no responses. Id like to keep my manifolds and put on a catted x....will I need a re tune. I know its a good idea but just wondering what the likely scenarios are...will it run rich/lean ? Mess up the idle ?I know that a re tune is the best way its just that the tune cost more than double what the part is. Any input is appreciated...maybe ill just order it and hang on to it till I get a fer more parts. Btw I already have a magnaflow cat back. Id love to get more sound/power but if its gonna screw things up without a tune I might hold off. Thanx in advance.