What causes a P2431 code?

P2431 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 P2431 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with P2431 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

P2431

Secondary Air Injection System Air Flow / Pressure Sensor Circuit Range / Performance

What it means

The Engine Control Module (ECM) detects an implausible or out-of-range signal from the air injection pressure sensor, typically indicating a mismatch between expected and actual air flow during system activation.