Thanks for the replies chaps... I don't have a Landy as yet but one I have my eye on has already EGR and CAT removed. Was just a little concerned if either had been removed due to a fault and then it rendered the vehicle un-MOT'able. Seems your answers have dulled my concerns.

Can a de CAT'd and de EGR'd vehicle be used only on private land? ie, will it fail its MOT without the CAT and EGR?