Ok so heres the deal...03 zx3 with short ram air intake and 2.5in cat back exhaust with obx muffler. Problem is i feel that ive let out to much back pressure? Should i switch pipe size? It feels like i lost power when i did the cat back. Also im thinking of getting some headers. 4-2-1 or shortys? I am trying to get some low end power so iono what i need to do. Please help.