I need a cat replacement with carb emissions..will a fed version bolt right up..is it an exact fit and if not what would it take to get it to work. I don't live in ny or cal and can't pay $700 for a $200 part..I'm told that using plug foulers to extend th 02 sensors is a way to get around it...my car runs fine so I don't see any mechanical reason to change it....HELP PLEASE...