Well a bit off topic from honda cars but I am still a loyal member of this forum and still enjoy honda's so I figured I would ask the expertshere, lol. Anyways I've been fully enjoying my 180sx so far but just recently had a new turbo/oil lines installed. I also had a Apexi Duel n1 exhaust system put on, at first the car was really loud and nice sounding, now all of a sudden the exhaust seems quieter inside and when at idle from outside has a rasp to it. Not sure if it was there before, the system since install has about 900km driving time on it, i tightened all the bolts i could. When i remove the exhaust from the downpipe back it sounds awsome so Im thinking of selling the cat-back on ebay or nissan forum and doing a custom 3.5" straight pipe setup. What could this noise be though? raspiness? System does have a res.