What causes a P2457 code?

P2457 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 P2457 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with P2457 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

P2457

EGR Cooler Efficiency Below Threshold

What it means

The Engine Control Module (ECM) has detected that the Exhaust Gas Recirculation (EGR) cooler is not sufficiently reducing the temperature of the exhaust gases entering the intake manifold.