it is an enzyme that speeds up chemical reactions.
The 1997 Thunderbird 4.6L engine has only 1 catalytic converter.
it chemically changes the fumes from the engine into carbon dioxide and water which keeps greenhouse gasses from building up quickly
You can't, it has to be replaced. It can be done easily and fairly cheaply by almost any muffler shop. Converters don't clog or wear out if engine is running efficiently. Look at other potential issues as well to avoid a repeat with new one. Running too rich is almost always the cause for a convertor failure, but you should not be running that rich for an extended period under normal conditions.