the size of the pipe at the back of the cat is the same on 1.8/8v/16v and vr6..and they all use a short connector piece that bolts between the cat back & downpipe and that reduces to a smaller bore on the 1.8 & 8v and if you change this to the 16v version the larger bore exhaust fit's (i don't think this is effected by year but I do know the earlier 16v uses the same cat as the 8v)