What does code P237A mean?

Q: What does code P237A mean?

O2 Sensor Exhaust Sample Error Bank 1 Sensor 2. P237A indicates that the powertrain control module has detected an exhaust sample error from the downstream oxygen sensor on bank 1, meaning the sensor's signal is not responding to exhaust changes as expected. The computer compares the rear sensor's output against expected behavior after the catalytic converter and flags the code when the sample is implausible or inconsistent.

DTC codes / P23xx · Ignition system and misfire / P237A

P237AO2 Sensor Exhaust Sample Error Bank 1 Sensor 2

P237A indicates that the powertrain control module has detected an exhaust sample error from the downstream oxygen sensor on bank 1, meaning the sensor's signal is not responding to exhaust changes as expected. The computer compares the rear sensor's output against expected behavior after the catalytic converter and flags the code when the sample is implausible or inconsistent.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaIgnition system and misfire

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.