Bugeye wagon rear box
 

My wagon has a full stainless system on it from what I have receipts for and previous owner said and after a brief look underneath looks to be all as told.
It does seem to differ a little though after a further look into it as I had been told the car had a full 3" system but after the underfloor decat it looks like it narrows a little before going into the cat back section and to me looks more like a 2.5" from that point backwards.

It currently has the wr sports rear on it which isn't to my liking and was looking to change it to the afterburner raptor rear section but after looking into it that is supplied as a 3" rear section although comes with the adaptor to connect to a 2.5".

My question is, if I do change to this rear box will I need to get the cars map reworked to take into account the rear box pipe length increase on diameter or will that not really make any difference.
Just checking as if it will need a map then may look into other bits first too so can do all at the same time and then get the map tweaked?

Thanks,
Craig