hi, i have a 98 honda civic lx(the one with the cat in front of the engine), and the header is cracked. it will cost 530 to buy a new one. i decided to buy aftermarket parts and replace the hole exhaust system. can anyone help me on what i need. i am planing on buying a header off ebay wich will get me back past the engine and i found a cat on nopi.com, total cost there about 200 bucks. what shoudl i do for the cat back system and what other hardware do i need to pull it off. what do i do with my 2nd o2 sensor.