2009 Nissan Maxima S, P0430 code
P0430: Catalyst System Efficency Below Threshold Bank 2

I know my catalyst system bank 2 is downstream because it’s bank 2 I just don’t know what part to buy to replace it? Is it the front right/left or rear right/left or something idk I just want to know what part to buy.

 

Actually bank 2 is at the front of the car and most likely, that cat by the radiator is toast, or at least mine was.

 

I second this. Bank 2 is by radiator side to match cylinders *2* -4-6 while Bank 1 is on the firewall side to match cylinders *1* -3-5