So I have a 96 GSR.

If i replace everything would an LS/Type R Exhaust would work as in change the Header, Cat, B-Pipe, Downpipe, and Muffler, as i still have my old LS as a parts car.

 

Yes it will work, don't spend too much on these parts as that the real JDM header is much better, and the exhaust doesn't flow all that great.

 

Ok, on the parts car has an Apexi WS2 Catback, and a Carsound High-Flow Cat and stock exhaust manifold, so can i use these parts, along with replacing the header with a DC Sports or Megan 4-2-1, and it wont throw any codes or anything?