i am thinking of fitting an st170 exhaust to my 1.6 focus, i have read and heard that this is possible, i am only wanting to fit from the cat back so keeping the original manifold, cat and flexi.

i was wondering if anyone had already done this because from what I've heard and seen (on youtube, admittedly not the most reliable source) that if you are keeping everything from the cat to the manifold standard then it is simply a case of undoing the bolts connecting the centre to the flange pulling the old system out and reversing the process to get the new system back in

can anyone with more knowledge than youtube experts shed a little light on this subject, would be greatly appreciated.