P0031 TOYOTA -

Question

Is it harmful to the engine to operate it with a "check engine" light on for P0031?

Answer 1

The P0031 code means that the Air-Fuel Ratio (A/F) Sensor Bank 1 Sensor 1 is not working properly. With the P0031 (or any engine code) the vehicle will fail the smog test and could make the engine run to rich ( engine will use more gas) and could eventually damage the catalytic converter.

In short, it depends on how you drive, type of gas you use and for how log you are planning the drive it with the bad sensor.