Hi.
Aside from the fact that the action would likely be quite noticeable (as soon as someone looks under the hood), and that, as far as I know, emissions regulations require a functioning catalytic converter, the oil mist it spits out usually doesn't cause any problems.
Only when it mixes with the soot component of the exhaust gas recirculation system does it form the "nice" sludge that deposits on the intake passages to varying degrees

.
(If you're already planning to drive illegally, a faulty EGR system is probably the least of your worries.)