The problem is that this truck was never designed form day one to be a performance truck. A new intake & exhaust will probably get you 10-15hp more, but then it will want more gas at the same time. That will encourage you to bury the throttle more & prematurely wear out that little engine. If you wanted a high performance truck then you should consider hunting down a GMC Cyclone. It's a turbo charged V6 engine mated to an awd system that will shred most of the trash out there. I don't consider that Mazda of yours to be good for anything but hauling wood & whatever fits in the bed.
