The best thing you can do is be alert for signs of trouble and head for a service facility if you suspect that the catalytic converter is malfunctioning.
Technicians will put your vehicle on an electronic diagnostic machine to locate the source of the problem, possibly remove the oxygen sensor from the exhaust manifold or exhaust pipe ahead of the catalytic converter to see if that changes things, and replace the catalytic converter, if necessary.
Here are five ways to tell that something may be wrong with your catalytic converter:
