P237B
O2 Sensor Exhaust Sample Error Bank 2 Sensor 2
O2 Sensor Exhaust Sample Error Bank 2 Sensor 2: the control module has detected this fault condition. (Code P237B)
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Common causes
Ordered by how often each turns out to be the cause.
- Sensing element or protective tube fouledCommon
- Sensor seal leaks - bypass air dilutes samplePossible
Parts involved
- Oxygen Sensor B2s2
- Exhaust After Catalyst B2
P237B is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.