Knowing you aren't too fussed over MOT checks in Malta, not going to say a word on emissions checks.
I think you have an O2 sensor after the CAT.
That may throw a wobbly and get emission nags
The primary sensor is the O2 before the CAT and apart from exhaust being a little more free flow should see little difference.
Well, cut off the muffler, and the car already sounds heaps better (with a tiny amount of turbo whistle to boot!) now just gotta get some $$$ and decat the thing and straightpipe it. Maybe down the line do a custom intake and remove the factory box and pop on an aftermarket filter for that induction sound too.
Coming back to this thread, is the exhaust difficult to remove from the turbo? (IE, the exhaust system starts and ends at the turbo) just wanna try something.