cat or lamda

I have a peugeot 406 1999 and the engine managment light comes on after
driving about 2 miles, I understand that it is telling me there is a
problem with either the cat converter on the lambda senser, but how do you
tell which one ,without the costly method of trail and error,

i would appreicate any advise

cheers

 

The engine management light usually means that there is a message waiting to
be read. The message may give you more information. You need to find a
garage (or Pug dealer) with the kit to download the message.

 

And there's a lot more things that put the light on than cat and
Lambda.