Here is a link to the emissions warranty information:

http://www.sema.org/content/?ID=22238

In my case, the dealer did all the research. At first I was quoted around $2000 for the diagnostics, parts, and labor to install a new catalytic converter. Thankfully, a couple of hours later the dealer called back and said that the parts and labor would be covered by the emissions warranty and my only costs were the diagnostic time.

This was my first trip to an MB dealer since acquiring the vehicle and I was very impressed. We were out of town, this would probably be our one and only visit to the dealer, but we were treated as if we were local customers. We did have to leave the vehicle and return a week later after the repair but this was a small price to pay compared with the cost of a new catalytic converter.