is a down pipe a full exhaust coming from the turbo without a muffler or would i need to buy more with it to finish it off to the end?

 

..... mk the dp comes straight off of the o2 housing that comes straight off the hotside of the turbo so it goes hotside , o2, dp , test pipe or cat , then catback you could run just a dp and it would increase horsepower but it would be loud and you'd sound like an srt-4 ( tx dump'd exhaust everywhere) so id say buy the whole exhaust and run a test pipe but if you need the car emission legal get a high flow cat

 

+1, Maybe the Term you looking for is TBE* that i think would save you lots of money+ time and shipping.

TBE* Turbo Back Exhaust (from the Turbocharger,or O2 housing on Evos, Back to the end of the car, usualy your choice of Test Pipe or highflow Cat)

At Catback is From the Catalytic converter Back, So minus a Downpipe and cat replacement peice.