What is the general train of thought on this mod, do right away or after warranty runs out? I just got my Z 3 weeks ago and if this stands a chance of voiding my warranty for engine troubles (if any come up later down the road) then it's something I'll wait on after the warranty runs out. My understanding is that the PC5, though not as good of a tune as an ECU flash will give, can be reverted back to stock if need be. Same for an ECU flash or once it's done there's no going back to stock?