A decat replaces the catalytic converter. It is just a straight through pipe. It means your car won't pass its MOT. You can buy the decat separately. If I had a 182, I would be buying a yozza exhaust with a decat. It frees up a little bit more power (2-4bhp) but sounds quite good.
So you're essentially buying the standard exhaust kit with an additional pipe?
So when your car needs an MOT what do you do? Put the CC back? How difficult a job is this? What does 'cat-back' mean then?