Check engine light is on on 2000 Mercury Cougar

I have been told this could be a "tube" stoped up in the motor. Has anyone had this problem before? The codes are T0420-CAT and t0401 EXTT or EXH GAS

1 answer 2 comments
Can you provide us with the code that caused the light to come on? Are yo talking about an EGR tube?
The codes are T0420 and T0401
The P0401 code can be from a plugged EGR tube or port, however I don't know if that will cause the P0420 code. Here is some info for both of the codes:
http://repairpal.com/OBD-II-Code-P0401
http://repairpal.com/OBD-II-Code-P0420