I did it guys! And what a difference! WOW I am keeping my stock Nismo exhaust and maybe getting y pipe. What y pipe is the best on the market right now? It sounds just like stock but amplified a bit. I highly reccomend this mod to anyone that has a Nismo and isn't looking to spend over $1000 on exhaust. The catback is already 2.5 inch piping. All that need replacing is the ypipe which is 2.25 in diameter. Sound clips will be up today after work.