So the system came on the bike when I bought it. I'm going to sell the bike and the system separately to recover more money. After I put the stock system back on, not only did I gain 20 noticeable pounds but it runs better and no need for a PC3. It works great. It's not nearly as loud as you'd think for such a small pipe. At idle it's fine but it wails at high RPM, sounds really, really good. Ask anyone that has one. They do make drop in db killers for like $25 on ebay you could try and I nearly did. I'd rate it a 6. The second pipe that has far less use would be a 5. They are also repackable. Just let me know, you're my only inquiry.