Our cars have a pre cat at the header, and my 1.6 only has one cat. If your car is California emissions equipped, you should have 2 cats and an egr. You can delete the cat with an obx longtube header like the one I have, but it is rediculiously loud. They sell on eBay for $175-200. Protophile might be able to source a thunder header from outside the country, but last I heard he was done with importing parts for the 1.6. Your car will bolt up directly to a mazdaspeed axleback muffler. When I put the mazdaspeed axleback on my car it made a nice exhaust note, but with the header it is so raspy that it sounds like it rattles itself. Just my .02 cents. There is a magnaflow exhaust on eBay for cheap, add a header, and you will see a power increase. The magnaflow deletes the resonator as well. I think the magnaflow is less than $250, which is really low price for such high quality. You can also look in the for sale section, there are always people selling exhaust parts. Just so you know most 99-03 aftermarket bolt on exhausts are interchangeable, except the header, header must be for a 1.6l. I also recommend upgrading the stock exhaust hangers to poly ones from corksport. Check out corksport.com they have alot of goodies for our cars, and excellent customer service. Protegefaq.net has alot of good info on protege specs.
