What causes a P0157 code?

P0157 can be triggered by several issues — see the verified probable causes and step-by-step diagnostics shared by mechanics and owners on OBDIY.

Can I drive with a P0157 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with P0157 active.

Follow the step-by-step diagnostic on this page, then read the verified fixes contributed by other Heavy Truck owners — the answer marked "Verified Cause" worked for the original poster.

OBDIY

OBD-II

P0157

O2 Sensor Circuit Low Voltage (Bank 2 Sensor 2)

What it means

Indicates the secondary oxygen sensor monitoring the catalyst effectiveness for the second bank of cylinders is reporting a voltage below the calibrated threshold, suggesting a lean condition or circuit failure.