2005 Nissan Altima Catalytic Conveter

Hi. About 2 months ago, my service engine light came on and showed the code p0430 "bank threshold 2" for catalytic converter. The light will come on for a good many miles then go off and won't come back on till about 3 weeks or later. I have not notice any significant changes with the performance of my car. My car drives fine & the gas mileage is great. I was wondering would I still need a new catalytic converter if so, what kind will I need? I think my car "2005 Nissan altima 3.5sl v6" has more than one catalytic converter