de cat/down pipe info

[Northy 8]

http://www.ebay.co.uk/itm/Milltek-L...arts_Vehicles_CarParts_SM&hash=item3f256a771c

Hi i am after a down pipe/de cat for my 172 cup
Will the above link part fit my stock manifold and stock cat back system
Says 2.5" bore which i am guessing is the same as renault parts
Thanks