this is what i was thinking of doing

grey area header from mazda trix
http://www.mazdatrix.com/e-gray.htm that replaces the two pre-cats

then to a Pre-Silencers from mazda trix
http://www.mazdatrix.com/r-8.htm

then to a CORK SPORT 'Power Series' Cat-Back Exhaust System
http://www.corksport.com/main.php3?p...tory59.content