Intermittant Catalytic converter failure

Hello,

First time poster in this newsgroup so please be gentle with me!!

I have recently (two weeks ago) acquired a Peugeot 406 2ltr 16v Rapier
Saloon on a '52 plate with just over 86000 miles on the clock. It has a full
Peugeot mail dealer service record etc which is why I wasn't concerned about
the mileage.

When I started her up this morning a message appeared (with three beeps)
that the Catalytic Converter had failed. I drove a short distance, stopped,
started the car after 20 minutes or so and was greeted with something like
'Pollution Control Failure' at which point I drove the 3 miles home
intending to have a look this afternoon.

I've just gone out to the car and started her up and there's no fault beep
or message.

The cat does look it's age but why would I get these failure messages this
morning and not this afternoon? I would have thought that if a cat has
failed, a cat has failed.

Please let me know if you need any more info.

Regards,

Richard