O2 sensors in pairs?

[Adam Roby]

Some on the interweeb suggest swapping out both sensors (in pairs) when you have an O2 sensor code.

I am getting P0137. I only checked because lately after driving a while, if I stop and start in a short time without cooling it has a hard time to start. I need to lightly touch the gas pedal to get it to start. When its cold she starts no problem, maybe due to the "choke" effect revving a bit higher. Not sure if the sensor can cause that but its worth a try.

Question is, do I just swap it, do I swap the pair (left & right or upstream (front) & downstream (rear)) and/or do I swap all 4? The code is for Bank 1 Sensor 2, if I am reading this right it seems the driver's side after the cat.

Recommendations?
Denso OK for this? Rockauto has them for $20 CAD, locally $70 + tax (each).

 

[Conundrum2006]

Get ngk brand. They are the oem.
You don’t have to swap pairs unless you want to, bank 1 sensor 2 sounds like a down stream sensor.
Personally I’d just replace the fault causing sensor.


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[KrazyK]

Po137 is typically a lean on bank 1 code. B4 attacking sensors i would check for vac.leaks around intake, failing fuel pump, or clogged fuel filter.

 

[KrazyK]

Bank 1 sensor 2 is driver side post cat but i would recommended checking what was listed in last post first

 

[Logan Savage]

I'd probably swap the two downstream sensors & see if the code follows the swap .

 

[Adam Roby]

I'd probably swap the two downstream sensors & see if the code follows the swap .

Yup, I was thinking the same thing. Figure these things are easy to take out or do they generally cause a lot of trouble?

 

[Conundrum2006]

Depends, on southern cars I’ve never had much trouble removing O2 sensors as long as there was access to the sensor. On cars from areas with salt on the road during the winter I’ve had a few where the original sensors wouldn’t break lose, even with a impact gun and heating with a torch.
I’ve got the standard O2 sensor socket kit for the 3/8 & 1/2 ratchets, a special pivoting wrench tool with O2 adapter for hard to reach sensors and a regular 22mm wrench.
On most the 22mm is plenty to break them lose, on hard to reach the sockets and ratchets work. For really stuck sensors PB blast and heat to persuade usually works.

Just be careful if the wires as you try to break it lose, just in case it doesn’t budge you wouldn’t want to cause a break on the wires making the sensor completely no good. As it is now it’s drivable.


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