# Trying to determine which O2 sensor is B2, S2 on 2011 VR6 Engine



## rcprato (Sep 14, 2007)

Posted this on ClubTouareg forum but figured could't hurt putting it here too

There is a disconnect here, VW Parts listings calls out the O2 sensors as Rear Oxygen Sensor, RIGHT or Rear Oxygen Sensor, LEFT and if you useVCDS to read your MIL you get the bad O2 sensor called out as Bank 2, Sensor 2
2947 - Oxygen (Lambda) Sensor Signal B2 S2
P2272 00 [096] - too Lean
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 4
Mileage: 166376 km
Date: 2018.02.20
Time: 11:42:47

Engine speed: 2204.50 /min
Normed load value: 27.8 %
Vehicle speed: 121 km/h
Coolant temperature: 96 °C
Intake air temperature: 27 °C
Ambient air pressure: 990 mbar
Voltage terminal 30: 14.418 V
Unlearning counter according OBD: 39
Oxygen sensor bank 1 sensor 2: response time: 0.00 s
Oxygen sensor aging test bank 1 after catalytic converter: 0.84 s
Rear cat conv temp main cat conv model value: 715.87 °C
Oxygen sensor bank 2 sensor 2: response time filtered: 0.03 s
Oxygen sensor aging test bank 2 after catalytic converter: 1.10 s

Considering the VR6 has exhaust and Cats on same side of the engine do you assume front Cat is B1 O2 Left sensors and rear Cat are B2 O2 Right sensors ?
http://o2sensors.com.au/static/o2-sensor-identification-and-locations

I'm guessing from VCDS scan B2, S2 is the rear post Cat O2 ?


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## SnakeEarl (Dec 11, 2013)

Bank 1 always has cylinder 1 in it. Sensor 2 is always the rear sensor if there are only 2 in-line sensors. Your vehicle has 4 total sensors, so Bank 2, Sensor 2 would be the after-cat sensor on the Bank2 manifold.


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## rcprato (Sep 14, 2007)

Thank you SnakeEarl, always good to get an answer from a knowledgeable source !

Still a little confused, VW Parts listings calls out the O2 sensors as Rear Oxygen Sensor, RIGHT or Rear Oxygen Sensor, LEFT so would R or L be Bank 1 ?

Like previously said both are on passenger side of engine.

I know when parts are called out "L" or "R" with suspension for example it is from sitting in driver seat looking forward so "L" is Driver Side


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## rcprato (Sep 14, 2007)

Turns out B1 is referred to as (L) and B2 is (R)

(L) O2 sensor is also related to Cylinder #1

On my VR6 engine the Bank 2 Post CAT O2 sensor would also be referred to as R/R or R/Post O2 sensor.

Can it be any more confusing and on top of that this is the hardest O2 sensor to get to........


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## SnakeEarl (Dec 11, 2013)

rcprato said:


> Turns out B1 is referred to as (L) and B2 is (R)
> 
> (L) O2 sensor is also related to Cylinder #1
> 
> ...


Yeah, you have to mentally "turn the engine sideways" in your head. Cylinder 1 is in the front. So if you look at it from the driver's side fender, the left manifold is Bank 1 and the Right is Bank 2.


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