I have a 2000 Maxima Nissan GLE I've been through two different sensors trying to figure out what the code P0430 for a "catalyst efficiency bank #2" is calling for.. a little help please ?

the last part I tried was a Denso 234-4270 Oxygen Sensor & my mechanic said it didn't even fit the car at all

 

Is your Max Cali or Fed spec? (Does it have 3 or 4 O2 sensors?)

Here is the diagram and parts from Courtesy Parts...
http://www.courtesyparts.com/maxima-...1988_1992.html

Could also be a bad catalytic converter.

 

Hey that's awesome ^^^^ Thanks.

 

how do i find out the number of sensors i have outside of asking my mechanic?

 

look under the car from the driver's side door...between the front and rear seat area you will see your main catalytic converter. If you see a little wire sticking out behind it, that's your one downstream O2 sensor which means you have a FED spec


TL/DR: Wire under = FED no wire=CALI

My guess is you have Cali spec, since both banks are being monitored...Fed spec doesn't monitor each bank separately.