This is bad for the environment........ Do what nissan says and replaced Both Catalytic converter to the tune of over $2000...
Oh and if you break anything doing this cheaper fix it's not my fault. What worked for me may not work for you.
Catalyst system efficiency below threshhold Bank 1 or 2...............right????????????????????
I have a crazy fix for this code but first alittle background.
I started throwing P430 which is the same code as you but for Bank 2 side. I played with it for months resetting the code and paying attention to when it would come back on. I can watch the O2 sensors with my scan tool and could tell from the freeze frame of the code it was only tripping the code because the efficiency was just barely out of tolerance every now and then. (HELL IT COULD BE BECAUSE OF THE 10% ETHANOL CRAP IN THE FUEL NOW!) Now sometimes I can drive a month and sometimes only a few days before the light would come on. Which basically means my Catalytic converters were only bad from an environment stand point and just barely. There's not anything really wrong with the pathfinder.
N-E-ways.... The BIG dollar fix is to replace back Catalytic converters which would cost quite a bit. Or trick the ECU into thinking that everything was just fine.
I choice the cheaper route. Only cost my $10 LOLOLOLOLOLOLOLOL
Here's what you need.
Buy a package of non foulers, Start small and slowly enlarge the hole all the way up to a 1/2" drill bit.
Now pull the rear O2 sensors and install the non-fouler onto the O2 sensor and then screw it back into the exhaust. I did it to both sides so they are the same. Everything only took my about 30 minutes.
Now the theory behind it is the O2 sensor is now pulled out of the direct stream of exhaust gases. Because of this it's seeing less of a sample of exhaust gases. Rear O2 sensors are not used to adjust air/fuel ratios. It's there for government emissions measuring. Now that it's seeing less of the bad stuff it's sending that signal to the ECU and the ECU likes it.
So far I've driven 8000 miles with this fix and haven't had a single problem and there's been NO LIGHT ON.
Fuel mileage didn't change AT ALL.
It worked for me!