I've been debating on what exhaust to go on my Z i originally wanted to go HKS dual ti hi power after watching sound clips on youtube i came to the conclusion i was going to go for the cheaper nismo dual exhaust...after doing some thinking about my Z i noticed that exhaust starts of from dual headers wich lead to dual cats wich connect to a y pipe that goes into a single pipe until its split into a dual exhaust at the cannister. Basically my question is should i just go single exhaust then? Cus the nismo exhaust is the exact same format as stock just a bigger diameter. One of my friends told me i should just run a custom set up were i have 2 single exhaust running from each cat wich i plan on replacing with test pipes soon....what do you guys think single or should i keep my holes filled and stay with dual?