Exhaust systems are probably not covered within the Porsche warranty t&c's, but it may be worth asking as my 997.2 with PSE had internal issues with one of its silencers and they fixed it, telling me that given the age and condition of my car, they had used their discretion and decided that a silencer failure should be fixed. This was around 3 years ago on a 2010 car with about 40k on the clock. You do have the the added issue of the bypass pipes being there, you'd have to re-fit the original centre silencer before discussing with the OPC.