Yeah, as Manny said, it looks more like an EGR fault. The HC numbers would be affected by a failed cat, whereas NOx is almost entirely the EGR system.

If you got ambitious when you're under the car some time, you might unhook your front section of exhaust, with the cat in it, and shake it upside down, see if anything falls out.
I found a bolt in an old car's exhaust... HOW someone managed to dump a bolt down the front end of the exhaust, I have NO idea, but it had done a good bit of damage to the front end of the cat, bouncing around in there!
I won't say you have one as well, but you may have small chunks of some sort of debris that could be dumped out.

__________________
-Josh
Testing the cheap Mercedes axiom, one bolt at a time...