The P2571: Direct Ozone Reduction Catalyst Temperature Sensor Circuit Intermittent/Erratic code indicates that the signal from the direct ozone reduction catalyst temperature sensor is inconsistent or fluctuating unexpectedly. This may be caused by faulty wiring, loose connections, or a failing sensor, leading to incorrect monitoring of the catalyst temperature and impacting emissions control.
P2571 – Quick Overview
Code | Information |
---|---|
Meaning | P2571: Direct Ozone Reduction Catalyst Temperature Sensor Circuit Intermittent/Erratic |
Is it serious? | Yes, an inconsistent or erratic sensor signal can lead to incorrect catalyst temperature regulation, which affects emissions control and potentially increases pollutant output. |
Possible causes | – Intermittent or erratic signal in the direct ozone reduction catalyst temperature sensor circuit – Faulty direct ozone reduction catalyst temperature sensor – Wiring or connector issues |
How to diagnose? | – Check for intermittent or erratic issues in the direct ozone reduction catalyst temperature sensor circuit – Inspect wiring and connectors – Test and possibly replace the direct ozone reduction catalyst temperature sensor |
P2571 Meaning
The P2571: Direct Ozone Reduction Catalyst Temperature Sensor Circuit Intermittent/Erratic code is triggered when the engine control module (ECM) detects unstable or erratic signals from the temperature sensor of the direct ozone reduction catalyst. Such behavior may result from loose connections, poor-quality wiring, or a malfunctioning sensor. These issues can prevent proper monitoring of the catalyst temperature, resulting in reduced efficiency of the emissions system.
Step-by-step diagnostic guide
Action | Description | Tools Needed |
---|---|---|
Check for Other Related Codes | Use an OBD-II scanner to determine if there are any additional fault codes related to the emissions system or sensor. This will help identify if there are more related issues. | OBD-II Scanner |
Check for Intermittent or Erratic Issues in the Circuit | Use an OBD-II scanner to monitor the live data from the sensor. Perform a wiggle test on the wiring while monitoring the sensor readings to see if movement causes fluctuations in the data. | OBD-II Scanner, Multimeter |
Inspect Wiring and Connectors | Visually inspect all wiring and connectors leading to and from the direct ozone reduction catalyst temperature sensor. Look for signs of damage, loose connections, or corrosion that could cause inconsistent signals. | Flashlight, Safety Gloves |
Test the Catalyst Temperature Sensor | Use a multimeter to measure the voltage or resistance from the temperature sensor. Ensure that the sensor’s output is stable and within manufacturer specifications when the vehicle is running. | Multimeter |
Repair or Replace Faulty Wiring/Connectors | Repair or replace any damaged or loose wiring and connectors. Secure all connections properly to avoid any potential future issues with intermittent signals. | Basic Tools, Replacement Parts |
Replace the Faulty Temperature Sensor | If the sensor itself is found to be inconsistent or provides erratic readings, replace it. Ensure the replacement sensor is compatible and properly installed. | Replacement Catalyst Temperature Sensor |
Clear the Code and Test Drive | After repairs are complete, use an OBD-II scanner to clear the fault code. Start the vehicle and monitor the sensor readings. Perform a test drive to ensure proper emissions control and stable catalyst temperature monitoring. | OBD-II Scanner, Vehicle Owner’s Manual |
Recheck for Codes | Re-scan the vehicle to verify that the P2571 code has been resolved. If the code persists, further diagnostics will be required to identify any remaining issues that may not have been addressed. | OBD-II Scanner |

OBD-II scanner Buyer’s Guide
- Scanner features explained
- Different types of scanners
- Scanners for coding/odometer/ECU/checks
- Best picks + discount codes
Download PDF Here (it’s free :))

Hi, I am Juraj “Yuri” Lukacko. I got frustrated by unhelpful and scammy mechanics, so I decided to learn everything about car diagnostics myself. I test dozens of new car diagnostic tools every month along with learning new strategies to fix and customize cars. About Juraj Lukacko (Yuri)