P2574 indicates that the vehicle’s direct ozone reduction catalyst (DORC) deterioration sensor is reporting a low voltage condition, meaning the sensor detects insufficient catalyst activity or a wiring fault.
The sensor itself can fail or become contaminated, causing it to read low voltage.
Damage, corrosion, or poor contact in the wiring harness or connector can produce a low signal.
The catalyst material may have deteriorated beyond its usable life, resulting in a genuine low sensor reading.
A poor engine‑ground point or a weak 5 V reference can cause the sensor circuit voltage to drop.
Rarely, the PCM’s sensor input driver can fail, but this is a last‑resort diagnosis after all hardware checks.
It is possible but uncommon. Most P2574 failures are due to the sensor, its wiring, or a degraded catalyst. Replacing the PCM should only be considered after confirming the sensor circuit is healthy.
If the catalyst has indeed deteriorated to the point where the sensor reads low, replacement will resolve the code. However, verify the sensor and wiring first, as they are more frequent culprits.
Yes. A low DORC sensor reading indicates insufficient catalytic activity, which can cause elevated emissions and may result in a failed emissions inspection.
Cleaning a corroded connector often restores proper signal and can clear the code, but the connector should be inspected for damage and the sensor voltage re‑checked after cleaning.