P0430 Catalytic Efficiency Below Threshold Bank 2

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

It doesnt relate to the code. However, the ECU may throw 'any' codes; maybe heres some info missin?

Have ECU zeroed (free at autozone or take batt cable off 30min) and see if the code reappears. Then youll possibly need new O2sensor before being passed inspection (?). Its relatively easy to DIY swap as/if proper tools ... 'some' info on links of this page http://www.cardomain.com/ride/748507/21

no, the crank sensor has nothing to do with a p0430 code. basically, the ecm sets the code when the front and rear o2 sensors start to mimic each other. meaning that the converter isnt able to store oxygen and the rear o2 sensor voltage changes rich to lean too quickly. have replaced a lot of these and thats most likely thats what you're gonna have to do.