Yes. Big ones. The primary cats performance are measured by 4 lambda (oxygen) sensors. 2 per bank, 1 pre cat sensor and 1 post car sensor. The Ecu will see that the cat is not working correctly and display cell codes 4021 & 4031 in addition to putting the car into limp home mode after a number of cel cycles.
The car will pass mot emissions due to the large secondary cats but your engine management will eventually shut down.
Search my last post - 4200 - 200 cell cats fitted.
Regards.