Recently changed my Peco single oval backbox for a DNX twin 3.5" and can't help but think I've lost acelleration although top end seems to be better now. I have a Remus race pipe so thinking the back preasure has dropped due to my new box having two exits instead of I talking bollocks or would a new cat back system solve this....Cheers, my cars a 1.8 sport with chip and induction kit.