Had our catalytic converter stolen last night removed with what a mechanic described as the sort of equipment the rescue services use to cut someone out of a wreck , proceeding with the insurance claim but concerned that the replacement could be taken and I've not seen any security system available that could withstand the sort of attack our car has just faced If we get the exhust system replaced but leave the catalytic converter out , put in a piece of straight pipe instead could it still get through the MOT ?