OBD-II code · Powertrain (generic, extended)
P237A O2 Sensor Exhaust Sample Error Bank 1 Sensor 2
O2 Sensor Exhaust Sample Error Bank 1 Sensor 2: the control module has detected this fault condition. (Code P237A)
Is it safe to drive with P237A?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySensing element or protective tube fouled with soot, oil or coolant
- PossibleSensor seal or thread leaks - bypass air dilutes sample
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.6–1.5 h
- Emissions test
- Likely to fail
- Parts involved
- Oxygen Sensor B1s2, Exhaust After Catalyst B1
Related codes
- P237BO2 Sensor Exhaust Sample Error Bank 2 Sensor 2
- P23A0O2 Sensor Exhaust Sample Error Bank 1 Sensor 2
- P23A1O2 Sensor Exhaust Sample Error Bank 2 Sensor 2
- P2414O2 Sensor Exhaust Sample Error Bank 1 Sensor 1
- P2377Turbocharger Inlet Pressure Sensor B Circuit High
- P2378Turbocharger Inlet Pressure Sensor B Circuit Intermittent or Erratic
- P2379O2 Sensor Out of Range During Deceleration Bank 2 Sensor 2
- P237CExhaust Heat Exchanger Bypass Valve A Control Circuit Open
- P237DExhaust Heat Exchanger Bypass Valve A Control Circuit Low
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.