P2572
Direct Ozone Reduction Catalyst Deterioration Sensor Circuit
Auxiliary emissions (ozone-reduction catalyst)
Generic OBD-II
Low
What it means
P2572 means the ECM has detected an electrical fault in the circuit for the direct ozone reduction (DOR) catalyst deterioration sensor. This catalyst — found on some very-low-emission vehicles — converts ground-level ozone as air passes through it, and the sensor monitors its condition. It's purely an emissions-monitoring fault: the engine runs normally, and the usual causes are the sensor or its wiring.
Low
Can I keep driving? Yes — the car drives normally; this is an emissions-monitoring sensor fault with no effect on running.
Common symptoms
What you'll notice
- Check-engine light on
- No noticeable change in how the car drives
- May fail an emissions/readiness test
Common causes
Most likely first
- Faulty direct ozone reduction (DOR) catalyst deterioration sensorLikely
- Open or shorted wiring in the sensor circuitCommon
- Corroded or loose sensor connectorCommon
- Poor ground or reference on the circuitLess often
- Faulty ECM/PCM input (least likely)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and confirm the code is current.
- Locate the DOR catalyst deterioration sensor and inspect its connector and wiring.
- Check the circuit for continuity and for shorts to power or ground.
- Test the sensor per manufacturer service data and replace it if faulty.
- Repair wiring or replace the sensor, clear the code, and re-test after a drive cycle.
FAQ
Quick answers
Is it safe to drive with P2572?+
Yes. The direct ozone reduction catalyst is an emissions feature on certain low-emission vehicles; a sensor circuit fault doesn't affect how the car runs, but fix it to pass emissions.
Can I just clear P2572?+
You can, but a faulty sensor or open circuit will set it again. Repair the sensor or wiring first.
Related codes
Often seen with P2572
Read & clear P2572 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX