OBD SCR Catalyst Incorrect
What it means
P24FE stands for SCR Catalyst Incorrect. P24FE is a P code, so the fault sits in the engine, transmission and emissions systems. For P24FE, the second digit places it in auxiliary emission controls. For P24FE, work through the cause list below, cheapest checks first.
What to check first
For P24FE, clear the code, drive a short distance and read it again, since a code that comes back is still there and one that does not was history.
Check these first
- P24FE: Carbon buildup or blockage in the EGR, EVAP, or air injection system
- P24FE: Failed solenoid, valve, or pump in the auxiliary emissions circuit
- P24FE: Wiring, connector, or fuse fault for the emission component
- P24FE: Small leaks in vacuum or EVAP lines
- P24FE: Failing catalytic converter or oxygen sensor reporting incorrectly
What to do next
P24FE is a fault in the auxiliary emission controls system. The steps below are general, so what actually failed on your vehicle may not be what P24FE names.
- P24FE: Read related codes and freeze frame with an OBD-II scanner
- P24FE: Inspect hoses, valves, and solenoids for leaks, cracks, or carbon buildup
- P24FE: Smoke test the EVAP or intake system if a leak is suspected
- P24FE: Command components on/off with a scan tool and watch them respond
- P24FE: Clean or replace the blocked or failed component
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Updated
Generic SAE J2012 definition. Last updated 2026-08-30.