Check engine light error code P0420 - 35 - 00 - - Need help!!! on 2003 Volkswagen Jetta

I am getting the following error code when I analyze my check engine light:

16804 - Catalyst System: Bank 1: Efficiency Below Threshold

P0420 - 35-00 - -

I checked some VW forums and it seems to be a catalytic converter issue. Something to do with the O2 sensors in the front and back. Could anyone give me an idea on what needs to be done and how much it would cost before I take it to a mechanic? I appreciate your response

Asked by for the 2003 Volkswagen Jetta
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