Emira I4 (US) P2000 Error Code

[Rainier]

Getting intermittent Check Engine Light with P2000 OBD2 error code.

Check Engine Light came on one day, automatically cleared itself the next day and came on again the third day.

I see that "The P2000 code indicates a problem with the NOx (Nitrous Oxides) trap efficiency" on Google search and that downstream Oxygen sensor is one possible issue.

Would welcome any Emira specific insights into this issue. (Dealer will take a look but I would welcome third party advice)