P2571 — Direct Ozone Reduction Catalyst Temperature Sensor Circuit Intermittent/Erratic

P2571 — Direct Ozone Reduction Catalyst Temperature Sensor Circuit Intermittent/Erratic. A fault in the catalytic converter efficiency monitoring. The car is usually drivable while you plan the repair. Typical causes: engine misfires damaging the catalyst, exhaust leak ahead of the converter, aged or contaminated catalytic converter.

powertrain (engine/transmission)

Is it safe to drive?

Short-term driving is OK Usually safe to drive for a limited time: the car remains drivable, but emissions are elevated and fuel economy suffers. Do not postpone if you notice power loss, overheating of the exhaust, or a strong smell — a clogged converter can damage the engine.

How to diagnose with an OBD scanner

  1. Read the code and freeze frame Connect an OBD2 scanner, confirm P2571 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
  2. Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
  3. Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the catalytic converter efficiency monitoring for damage, corrosion, chafing or poor contact.
  4. Subsystem check Compare upstream and downstream O2 sensor waveforms in live data — a healthy converter smooths the rear signal.
  5. Subsystem check Check for exhaust leaks and rule out misfire codes before condemning the converter.
  6. Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P2571 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for P2571 (parts and labor, USD, independent shop rates): Repair an exhaust leak: $100–$350; Replace the catalytic converter: $800–$2,500; Replace an oxygen sensor: $150–$450. Overall, fixing P2571 usually costs between $100 and $2,500. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

Will P2571 clear itself?

Sometimes P2571 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

How do I diagnose P2571 myself?

Start with a scan: confirm P2571, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the catalytic converter efficiency monitoring, and verify the suspect component against live data before buying parts.

What is the most common cause of P2571?

The most common causes are: engine misfires damaging the catalyst, exhaust leak ahead of the converter, aged or contaminated catalytic converter.

What are the symptoms of P2571?

Drivers most often notice: increased fuel consumption, Check Engine Light on, slight loss of power at high rpm, failed emissions test.

What does OBD2 code P2571 mean?

P2571 — Direct Ozone Reduction Catalyst Temperature Sensor Circuit Intermittent/Erratic. A fault in the catalytic converter efficiency monitoring. The car is usually drivable while you plan the repair. Typical causes: engine misfires damaging the catalyst, exhaust leak ahead of the converter, aged or contaminated catalytic converter.

What does P2571 mean?

P2571 is logged by the onboard diagnostics when the catalytic converter efficiency monitoring does not behave as expected. The official definition is “Direct Ozone Reduction Catalyst Temperature Sensor Circuit Intermittent/Erratic”. This is a powertrain (engine/transmission) category code.

The module monitors this system continuously while driving. When readings fall outside the expected range for a defined number of drive cycles, it stores P2571 and switches on the warning light. Freeze frame data saved with the code shows the exact conditions — rpm, load, temperature, speed — at the moment the fault was detected, which is the best starting point for diagnosis.

What causes P2571?

  • faulty downstream or upstream oxygen sensor
  • persistent rich or lean fuel mixture
  • aged or contaminated catalytic converter
  • engine misfires damaging the catalyst
  • oil or coolant entering the exhaust

Common symptoms of P2571

  • increased fuel consumption
  • Check Engine Light on
  • slight loss of power at high rpm
  • failed emissions test
  • sulfur or rotten-egg smell from the exhaust
  • rattling noise from under the car

How to diagnose P2571

  1. Connect an OBD2 scanner, confirm P2571 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
  2. Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
  3. Visually inspect the wiring harness and connectors related to the catalytic converter efficiency monitoring for damage, corrosion, chafing or poor contact.
  4. Compare upstream and downstream O2 sensor waveforms in live data — a healthy converter smooths the rear signal.
  5. Check for exhaust leaks and rule out misfire codes before condemning the converter.
  6. Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P2571 does not return.

How to fix P2571

Start with the cheapest and most common causes before replacing expensive parts:

  • Repair an exhaust leak — $100–$350
  • Replace the catalytic converter — $800–$2,500
  • Replace an oxygen sensor — $150–$450

How much does it cost to fix P2571?

Repair cost depends on which component actually failed. Typical scenarios for P2571 (parts and labor, USD, independent shop rates):

  • Repair an exhaust leak: $100–$350
  • Replace the catalytic converter: $800–$2,500
  • Replace an oxygen sensor: $150–$450

Overall, fixing P2571 usually costs between $100 and $2,500. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Can you drive with P2571?

Usually safe to drive for a limited time: the car remains drivable, but emissions are elevated and fuel economy suffers. Do not postpone if you notice power loss, overheating of the exhaust, or a strong smell — a clogged converter can damage the engine.

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