I have a 2012 ZX14 and recently bought a Yoshimura R-77 for it. My understanding was that in order to maximiize performance I needed a Power Commander along with an ECU upgrade. I spoke with someone at Guhl Motorsports today who told me that their ECU upgrades can include fuel mapping for this pipe thus negating the need for the PC. Anyone have any experience with this who can educate me? Is Guhl the way to go? Also, do I need block off plates or can I fix the backfire issue by connecting or plugging the hoses? Thanks!!