Generally this is going to be an indicator or a fuel problem, as the engine is sending too much raw fuel to the cat to burn. First things to check would be spark plugs or wires. Running with a cat burning red hot for long can cause the cat to fail, and in worse senarios even burn through the floorboard.
Partially clogged! Y-THINK-Y
The converter is plugged and needs to be replaced
Yes, an engine misfire will cause this and will ruin the converter. It may also be partially clogged.
A partially clogged converter will cause this. Also an overly rich fuel/air mixture or a cylinder misfire is a cause.
Converters get hot when they operate and this is normal. However a partially clogged converter will get excessively hot and my even turn red. This will cause a loss of power, stalling, and surging.
It is either clogged and needs replacing or you have one or more cylinders that is not firing properly and unburnt fuel is being ignited in the converter. On an 18 year old car I would suspect the converter is clogged.
Your converter is clogged and needs replacing.
most likely you have a leak in the exhaust pipes or a bad catalytic converter
If the catalytic converter is removed the computer will turn on the check engine light, and fuel economy may suffer.
An engine that burns oil will usually foul the spark plugs. That, in turn will cause ignition misfire, higher emissions and likely damage the catalytic converter.
The platinum in the catalytic converter. a lug nut would be easiest. A piece of the antenna could be coiled into a ring.
It is clogged or you have a miss on the driver side bank of the engine which is causing raw fuel to be dumped into the converter where it is burning. If you find your engine is running fine and has no miss then the converter is clogged.