From
http://www.motuk.co.uk/manual_730.htm<The catalyst test is part of the MOT test for most spark ignition petrol engined passenger cars with four or more wheels first used on and after 1 August 1992.>
I don't think the Rover engine will emit to cat standards without one, there are folk saying they've removed the cat and got away with it, but whether all test centres would pass the car I rather doubt.
