What does code P1140 mean?

Q: What does code P1140 mean?

O2 Sensor Sluggish (Bank 1 Sensor 2). P1140 on a GM vehicle means the powertrain control module has determined that the downstream oxygen sensor on bank 1 (Sensor 2, after the catalytic converter) is responding too slowly to changes in exhaust oxygen content. The computer monitors the sensor's voltage switching rate and compares it to an expected response time, flagging the code when the signal remains lazy or flat for too long.

DTC codes / GM codes / P1140

P1140 · GMO2 Sensor Sluggish (Bank 1 Sensor 2)

P1140 on a GM vehicle means the powertrain control module has determined that the downstream oxygen sensor on bank 1 (Sensor 2, after the catalytic converter) is responding too slowly to changes in exhaust oxygen content. The computer monitors the sensor's voltage switching rate and compares it to an expected response time, flagging the code when the signal remains lazy or flat for too long.

SystemPowertrain

Code typeGM specific

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering

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