How the converter fails determines its effect on the engine running. In your case the coating inside the unit is worn and it is no longer working. That could be from age (most likely) or possibly the engine is running slightly rich or burning a small amount of oil, both can cause the converter to fail. This failure mode will not really change how the engine runs it just sets the code.
Now, if the internals fail mechanically and get melted or broken, then it can cause a restriction that will change how the engine operates. In those cases you can have poor acceleration or large power losses, engine running hot and other issues. That is because the exhaust cannot leave the system and the engine chokes on it.
Thursday, December 21st, 2017 AT 5:49 AM