P2572: Direct Ozone Reduction Catalyst Deterioration Sensor Circuit
What to do
There is nothing to feel here and nothing mechanically wrong — this system has no connection to the engine at all. It exists to convert ozone in the air passing through the radiator into ordinary oxygen, and this code says the module cannot read the sensor that checks whether the coating is still doing that.
The reason to fix it is emissions testing, since the monitor cannot complete and the vehicle may be unable to take a test even though it runs perfectly.
Ask for the connector and the wiring at the front of the car to be inspected before the sensor is replaced. It sits where road salt, water and stones collect, and that is where these faults usually are.
What this code means
A fault in the circuit of the sensor used to assess whether the direct ozone reduction catalyst is still working.
P2567 explains what this catalyst is — a catalytic coating on the radiator that converts ozone in the passing air into ordinary oxygen, cleaning air the vehicle never dirtied. That family of codes watches the coating's temperature, because the conversion only happens within a working band. This code belongs to the other half of the same monitor: not how hot the coating is, but whether it is still converting anything.
The distinction matters diagnostically, because the two sensors fail independently and produce different codes on the same system. A temperature fault says the module cannot tell whether the catalyst is in its window. A deterioration fault says the module cannot tell whether there is any working catalyst there at all. Both stop the monitor completing; neither touches the engine.
What has gone wrong here is the circuit rather than the catalyst — an open, a short, a corroded plug or a failed reference supply. The verdict on the coating itself is P2577, and a reader who has that code as well should start there.
Everything about the location applies as it does at P2567: this equipment lives at the very front of the vehicle, in the path of road salt, water, grit and stone chips, so connector and wiring faults dominate over sensor failure.
Likely causes
Start here
- Corroded or loose connector · easy
- Damaged wiring harness · moderate
- Faulty ozone reduction catalyst deterioration sensor · moderate
Less common
- Wiring shorted to ground · moderate
- Failed sensor reference voltage supply · moderate
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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