What causes a SPN 457 code?

SPN 457 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 SPN 457 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 457 active.

How do I fix SPN 457?

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

J1939 SPN

SPN 457

J1939 SPN 457 — Fuel/Air parameter

What it means

SPN 457 is a general diagnostic code indicating that the Engine Control Module (ECM) has detected an irrational relationship between fuel delivery and air intake. It essentially means the air-fuel ratio is outside of the expected map.