P2571
Direct Ozone Reduction Catalyst Temperature Sensor Circuit Intermittent/Erratic
Auxiliary emissions / ozone-reduction catalyst
Generic OBD-II
Low
What it means
P2571 means the temperature sensor for the direct-ozone-reduction catalyst — a radiator-mounted catalyst used on some low-emission vehicles — is sending an intermittent or erratic signal. The ECM uses this reading to monitor the catalyst's operation for emissions purposes. Because the fault is intermittent, it most often traces to a loose or chafed connector rather than a failed sensor, and it does not affect how the engine drives.
Low
Can I keep driving? Safe to drive; this is an emissions-monitoring sensor and does not affect how the engine runs.
Common symptoms
What you'll notice
- Check-engine light on
- Usually no noticeable driving symptom
- May fail an emissions-readiness or smog check
Common causes
Most likely first
- Loose or chafed sensor wiring or connector (common with intermittent faults)Likely
- Failing temperature sensorCommon
- Corroded connector contactsCommon
- Harness damage near the sensorLess often
How to diagnose & fix
Work through it in order
- Wiggle-test the wiring while watching the sensor's live data for dropouts.
- Inspect the sensor connector and harness for chafing or corrosion.
- Measure the sensor resistance against specification.
- Repair or clean the connector.
- Replace the sensor if the signal keeps cutting out.
FAQ
Quick answers
Is it safe to drive with P2571?+
Yes. It monitors an emissions catalyst and doesn't affect drivability, though it can block emissions readiness until fixed.
Can I just clear P2571?+
It will return the next time the signal glitches. Because it is intermittent, check the wiring and connector first.
Related codes
Often seen with P2571
Read & clear P2571 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