P0430 Catalytic Efficiency Below Threshold Bank 2

[ramon09]

I have a 2000 Nissan Maxima with about 125000 miles. Just recently the check engine came on so I ran a diagnostic on it and it's coming up with the code P0430 Catalytic Effiency Below Threshold Bank 2. I have seen posting with people saying that it could either be an oxygen sensor or catalytic converter. I called a buddy of mine who works for Nissan and he asked on of the techs what his thoughts were. They told me that I may need to replace my Crankshaft Position Sensors. I really don't know much about cars but I was wondering how this part relates to this code, or if anyone has had to change this part out before?

any help would be greatly appreciated