I have a stock sytem right now and i want o make it a little louder. I dont want to buy new down pipes but just change out the muffler or the cat back i think its called, the big block thing before the muffler. I checked under the car and i dont think the muffler is permanatly attatched to the big round thing not quiet sure. I notice that there are two down pipes that connect to it and i can completely remove the whole exhaust and the cat back. If i did that would i just need to get test pipes and exhaust tips? If im wrong about somthing please tell me, ill learn. 