Powertrain
generic / SAE
P237B
O2 Sensor Exhaust Sample Error Bank 2 Sensor 2
The post-catalyst lambda sensor on bank 2 cannot acquire a valid exhaust sample - the signal does not respond to the expected exhaust composition during the diagnostic window. Typical causes are a fouled sensing element, a clogged sensor body or an installation leak that bypasses exhaust around the sensor.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number3 / 7B
Possible causes
- Sensing element or protective tube fouled high
- Sensor seal leaks - bypass air dilutes sample medium
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Inspection / repair
- Difficulty: medium
- DIY: possible
- Estimated cost: 120–350 €
- Estimated time: 0.6–1.5 h
- Component: oxygen sensor b2s2
- Component: exhaust after catalyst b2
- MIL / check engine light
- emissions-relevant
Sources
References
sae:J2012