What causes a SPN 2291 code?

SPN 2291 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 2291 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 2291 active.

How do I fix SPN 2291?

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 2291

J1939 SPN 2291 — Aftertreatment/Emissions parameter

What it means

Aftertreatment Particulate Matter Sensor Response. Sensor is taking too long to respond to changes in soot flow.