2006 Toyota Landcruiser engine warning light

Hi have a problem
have had a new exhaust system fitted to the landcruiser, extractors, new cat converters, pipes the whole lot but the engine warning ligh tcoming on have had it reset but still comes back on, the computer is saying that the sensors in the cats have too high flow they have packed the sensors out but no good any ideas dont really want to put the old cats back on