P2574: Direct Ozone Reduction Catalyst Deterioration Sensor Circuit Low
The P2574 code indicates that the Powertrain Control Module (PCM) has detected a low voltage condition in the circuit of the Direct Ozone Reduction (DOR) catalyst deterioration sensor. This sensor monitors the efficiency of the DOR catalyst, which reduces ozone emissions. A low circuit voltage typically points to a faulty sensor, wiring issues, or a poor electrical connection. This can lead to inaccurate catalyst monitoring and potential emissions non-compliance.
01. Most Common Causes
- Faulty DOR catalyst deterioration sensor
- Open or shorted wiring in sensor circuit
- Poor electrical connection at sensor or PCM
- Corroded or damaged connector pins
- Failed PCM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Failed emissions test
- Possible reduced fuel economy
- No noticeable drivability issues in most cases
03. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm P2574 and check for other codes.
Step 2: Visually inspect the DOR sensor and its wiring for damage, corrosion, or loose connections.
Step 3: Test the sensor circuit voltage with a multimeter; compare to manufacturer specifications.
Step 4: If voltage is low, disconnect the sensor and check for continuity and shorts in the wiring.
Step 5: Replace the sensor if circuit tests are normal but voltage remains low; clear code and retest.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
Yes, it is generally safe to drive short distances, but the vehicle may fail an emissions test and the Check Engine Light will stay on. Prolonged driving could lead to catalyst damage if the underlying issue is not addressed.
How much does it cost to fix?▼
The typical repair cost ranges from $50 to $150, including parts and labor. The sensor itself is often inexpensive, but diagnostic time may add to the cost.