GRP Engineering 4.5" stainless steel dump pipe including 3" mid pipe.
GRP have designed this to suit standard or aftermarket cat back exhaust systems, they have solid mounted the factory rear system in the exact location on their own vehicle for the design to ensure precise alignment to the rest of your existing system. This upgraded front section uses a HUGE 4.5" expansion pipe directly from the turbocharger into the extreme high flow 5" cat removing both of the restrictive factory catalytic convertors. Increased performance, deaper exhaust note and more turbo noise can be expected with this bolt on upgrade, with no tuning we had no Cel/Engine lights on the test vehicle for the first 1000kms. (A very small number of customers have experienced random Cel lights after extended driving periods, these have been easily cleared within seconds via $30 obd2 scan tools or obd2 bluetooth phone apps, and no noticable effects to performance with the dash light on).