2006 Pathfinder Upstream O2s

[Bluestream]

Had a P2A00 code and replaced Bank 1 Sensor 1 O2. Code gone now. With scantool reading voltages on new sensor (B1S1) reading around .29-.3 volts and B2S1 reading around .59-.60 Volts. When lean in decel volts just to .85ish on B1S1 and 1.27 on old sensor B2

Should I also replace B2S1 so both side are more closely aligned in their readings?

TKS in advance.

 

[Trav]

That is not how this works, they are both independent operators monitoring two different cylinder banks. Sure it could be a bit lazy in its switching times but swapping it is not necessarily going to make it similar to the other one.
Fuel trim and live O2/AFM data should be monitored to diagnose what is going on with each bank.

There are things that can effect one bank or the other and things that can effect both, the scan tool can help in determine that. An air leak after the MAF before or at the throttle body will most likely effect both banks, a leak in the intake may effect the bank closest to the leak source for example.
A dirty or open injector will effect the O2 readings on the bank it is in for another example. The O2 is just monitoring and sending info to the ECM so it can adjust the systems.

 

[Bluestream]

Trav, I get that there are other variables to the O2 readings such as air leaks , injectors ect. Let assume all things equal. Most all O2 manufacturers web sites recommend replace them in pairs (fronts, rears) Just looking for some real world experiences.

On my old Explorer when I replaced the fronts I got 5-10% MPG gains on Hwy, 4-5% in city

 

[Trav]

When they are under $50 ea sure but some AFM can get significantly over $100 ea, I think twice if its functioning well. If it has over 100K then its probably getting a little tired.
I never replace the rear monitor unless its throwing a code or a model that actually uses the rear O2 to assist in controlling the AFR. JMO.