I was wondering if the bank 2 sensor 2 (red) has any important function besides just monitoring whether the precat is working and if I can just use an O2 simulator to get rid of the SEL?

 

Can you please tell code number?!

I have currently (amd recently) a P-0430 "Catalyst System Efficiency Below Threshold (bank 2)"



I want to know if you have the same code.


TIA


BB

 

The rear O2 sensor for the calf. spec cars (most of 2000 and up) only looks at the pre-cat function and does nothing as far as controling air-fuel mixture (as opposed to the front o2 sensors)

You can replace the function of the rear o2 sensors with a sim. to fool the ECU into thinking the pre-cats are working fine.

However, you should know that there is a TSB concerning pre-mature failure of the rear o2 sensors. Nissan will replace both rear sensors and reprogram the ECU to prevent early failure. (some of the charge may be covered by the extended emmissons warrentee, but don't count on it)

http://maxima.theowensfamily.com/tsb/NTB02-051a.pdf

So you have three choices:

1. Do a sim.

2. Go to Nissan

3. Just replace the rear 02 sensor yourself without the re-program of the ECU (or have your local mechanic do it)


I had a similar code po158, and decided on choice #3. I figured I didn't want to waste time going to the dealer, and I didn't like the idea of cutting the wires up to do the sim, especially if I ever sell the car. So far the code has not returned after 8 months.

As far as code PO430 (second post) it means there may be something wrong with the cat and I don't know if just replacing the O2 sensors will help. According to the service manual:

P0430 Possible Causes:

Three way catalyst (Manifold)
Exhaust tube
Intake air leaks
Injectors
Injector leaks
Spark plug
Improper ignition timing


Good luck. Hope this helps!