Catalytic converter replacement on subaru

Here’s another question. I was recently told by a subaru dealer service shop that there was a part on my catalytic converter that would need replacing soon. He said it’s just one section of the whole part, but they only replace the cat. conv. as one unit, due to law/regulation. I’m new to car repairs and car talk, and I just want to make sure he’s being honest with me. Estimated cost of a replacing the new converter was $1700.

Btw, my subaru (new to me, bought used 2 yrs ago) only has 137,000 miles. I’m finding this hard to swallow.

Does anyone know if it is law to have to replace the entire unit now if only one little part on it is bad? I will get a second opinion, but still would like to hear thoughts.

I would start with finding out why you need a part replaced and what part are they talking about.  Then go to a local  [b] INDEPENDENT[/b] mechanic and found out what they say. Dealers, while no worse than independent mechanics, they tend to be more expensive.  

That said 137,000 miles in not what I would call "only"  That is not too soon to be requiring that service.