CORSA Performance NPP Only C8 Exhaust. V8 Sound, Controlled. The CORSA Performance C8 NPP Only exhaust puts control at the driver's finger tips. The NPP Only C8 exhaust allows the driver to maintain full control of the C8 Corvette sound profile with fully functional CORSA Cast NPP valves that integrate seamlessly to the stock C8 actuators. Each NPP system is both Louder (9 decibels) and quieter ( - 1 decibel) than that stock system and incorporates CORSA's proprietary RSC(R) Technology providing a drone free driving experience while still allow the 6.2L LT2 engine to release aggressive exhaust notes under heavy acceleration. This system replaces the AFM valve with a machined simulator bracket engineered specifically to prevent an AFM Check Engine Light. Perfect for aggressive drivers who plan on driving primarily in 'Track' Mode.