Hey all what's up... I have a custom cat back HKS carbon Fiber exhaust with 2.5inch pipe, I was thinking of getting a apexi 2.5 downpipe with high flow cat. will this set up make the car really loud. Because I live in CA, and you can't have your muffler too loud. Also is there a sliencer for the HKS carbon Fiber muffler? Do you think it's gonna help alot on reducing the sound of the car?