O2 Lambda Sensor errors with Engine Warning Light & VCDS scan - Cause?

[Elmura]

​Hey guys, on my v6 BWS engine Passat CC (MY12), I'm getting engine warning light. Car is approx 100,000km old. Plugged in VCDS & got following:


8218 - Post-Catalyst Oxygen (Lambda) Sensor Correction; Bank 2
P2098 00 [237] - Too Lean
MIL ON - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Mileage: 101826 km
Date: 2085.14.28
Time: 14:01:42




Engine speed: 2213.50 /min
Normed load value: 43.1 %
Vehicle speed: 110 km/h
Coolant temperature: 96 °C
Intake air temperature: 39 °C
Ambient air pressure: 1000 mbar
Voltage terminal 30: 13.099 V
Unlearning counter according OBD: 40
Oxygen sensor bank 2 sensor 1: specified value: 1.0000
Oxy sensor 1 bank 2 char curve offset: -0.03503
Oxygen sensor 1 bank 1 fast offset adaptation counter: 255
Oxy sensor 1 bank 2 offset spec value: -0.00211
Test of oxygen sensors bank 2: Delta-Lambda: -0.00003




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: 3
Mileage: 100435 km
Date: 2085.14.09
Time: 18:34:01




Engine speed: 2226.50 /min
Normed load value: 49.8 %
Vehicle speed: 111 km/h
Coolant temperature: 95 °C
Intake air temperature: 37 °C
Ambient air pressure: 1010 mbar
Voltage terminal 30: 14.135 V
Unlearning counter according OBD: 33
Rear cat conv temp main cat conv model value: 601.73 °C




4120 - Oxygen (Lambda) Sensor B2 S1
P2198 00 [237] - Signal too High (Rich)
MIL ON - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Mileage: 102005 km
Date: 2085.14.28
Time: 15:52:41




Engine speed: 2194.00 /min
Normed load value: 32.9 %
Vehicle speed: 109 km/h
Coolant temperature: 95 °C
Intake air temperature: 42 °C
Ambient air pressure: 1000 mbar
Voltage terminal 30: 13.122 V
Unlearning counter according OBD: 40
Oxygen sensor bank 2 sensor 1: specified value: 1.0000
Oxy sensor 1 bank 2 char curve offset: -0.05902
Oxygen sensor 1 bank 1 fast offset adaptation counter: 238
Oxy sensor 1 bank 2 offset spec value: -0.00204
Test of oxygen sensors bank 2: Delta-Lambda: 0.0000


I had another "Too Lean" error 8218 a couple months ago that I cleared.
Is this a sensor fault, a Cat issue or something else? I wouldn't expect a O2 sensor to fail at only 100,000km (but I do have a long Japanese car history)

[3C4M Guy]

Whilst you might not expect an O2 sensor to fail at 100K, I had an O2 sensor before the cat fail on my 3.2L V6 at 65K. It failed due to signal circuit shorted to heater circuit. It's very easy to replace the wrong side and I replaced both left and right. My car is an 2006 build so you'd think VW would have figured out how to build quality O2 sensors by 2012.

[guile]

I don’t think VW make them mate, it will more than likely be a Bosch part. I just replaced both pre and post cat on my car...

Could be worth removeing and using some sensor cleaner first and reinstalling to see if that is a short term fix...

[Elmura]

Strange thing is that sensors on both sides of the Bank 2 Cat are getting odd results... It could be faulty wiring, bad connection...

[shaunbags]

so what ended up happening with this one? ive got a v6 throwing P2098 & P2198 also...seemed a bit odd to have 2 bad sensors at the same time.

[Elmura]

so what ended up happening with this one? ive got a v6 throwing P2098 & P2198 also...seemed a bit odd to have 2 bad sensors at the same time.

Haven't done anything about it TBH. I did a scan recently after getting my car back from panel repairers (hail damage) and don't recall seeing the error again. Are you having similar issue?

[Coj]

so what ended up happening with this one? ive got a v6 throwing P2098 & P2198 also...seemed a bit odd to have 2 bad sensors at the same time.

I have these exact same codes and wondering what your solution was @Shaunbags

[Elmura]

For me, I just left it. The engine light is gone, but the VCDS scan still shows up as too lean. I have an exhaust cutout and whilst it doesn't get much use these days (my wife drives it predominantly), I do wonder if the lean sense is due to exterior air getting sucked back in on the overrun through the exhaust cutout when open.
Hasn't seemed to affect overall driving performance so I've just left it alone.
PS - my car is now 203,000kms and apart from a few niggly faults, it's still good.