Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that a sensor in your car that checks the temperature of a special part that helps reduce pollution is not working correctly.
The P143B code indicates that the Direct Ozone Reduction Catalyst Temperature Sensor is sending incorrect or unexpected signals to the vehicle's engine control module.
The Direct Ozone Reduction Catalyst is a component designed to reduce ozone emissions from the vehicle. The temperature sensor associated with this catalyst monitors its operating temperature to ensure it functions correctly. If the sensor sends signals that are outside the expected range, the engine control module will trigger the P143B code.
• Check Engine Light illuminated
• Possible decrease in fuel efficiency
• Potential increase in emissions
• Faulty temperature sensor
• Wiring issues or poor connections
• Failed Direct Ozone Reduction Catalyst
Catalyst: A substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change.
OBD-II: On-Board Diagnostics, a standardized system in vehicles for self-diagnosing and reporting.
• Use an OBD-II scanner to confirm the code.
• Inspect the temperature sensor and its wiring for damage.
• Test the sensor's output with a multimeter.
• Replace the faulty temperature sensor.
• Repair or replace damaged wiring or connectors.
• Replace the Direct Ozone Reduction Catalyst if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$100 - $500
Moderate
• Toyota Prius
• Honda Accord Hybrid
• Ford Fusion Hybrid
• Regular maintenance and inspections
• Ensure proper electrical connections
• Use high-quality fuel
Sensor Issue
• Have the vehicle inspected by a professional.
• Avoid prolonged driving until the issue is resolved.
Check if the vehicle's emissions warranty covers sensor replacement.
This code has been more prevalent in hybrid vehicles due to their advanced emission control systems.
Moderate – It should be addressed soon to avoid potential emissions test failure.
Driving with this code may lead to increased emissions, which could be against environmental regulations.
• Engine at operating temperature
• Vehicle in a controlled environment
The temperature sensor is typically located near the Direct Ozone Reduction Catalyst, which is part of the vehicle's exhaust system.
Q: Can I drive my car with this code?
A: It's possible, but it's best to have it checked soon to avoid potential issues with emissions.
Q: Will this code affect my car's performance?
A: It might not affect performance immediately, but it could lead to increased emissions and reduced fuel efficiency.
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Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
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Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
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Fitment Required · Vehicle-fitment part
Relevant when catalyst-efficiency or emissions faults persist after proper diagnosis.
Catalyst-efficiency faults sometimes point toward converter problems after proper testing.
Catalytic converters are highly vehicle-specific and should not be purchased by code alone.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.