P2431 Code - Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1
Quick Answer
The P2431 diagnostic trouble code (DTC) refers to a fault in the Secondary Air Injection (AIR) System Air Flow/Pressure Sensor Circuit for Bank 1. Common causes include Faulty Air Flow/Pressure Sensor: The sensor itself may be malfunctioning and providing incorrect readings, Clogged Air Filter: A clogged air filter can restrict the flow of air through the system, leading to incorrect sensor readings, Leaks in the System: Any leaks in the AIR system can disrupt the flow of air and cause the sensor to detect abnormal readings. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P2431 indicates Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1.
- Common causes
- Common causes include Faulty Air Flow/Pressure Sensor: The sensor itself may be malfunctioning and providing incorrect readings, Clogged Air Filter: A clogged air filter can restrict the flow of air through the system, leading to incorrect sensor readings, Leaks in the System: Any leaks in the AIR system can disrupt the flow of air and cause the sensor to detect abnormal readings.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
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Code P2431 Description
The P2431 diagnostic trouble code (DTC) refers to a fault in the Secondary Air Injection (AIR) System Air Flow/Pressure Sensor Circuit for Bank 1. The Secondary Air Injection System is responsible for reducing harmful emissions by injecting fresh air into the exhaust system to help burn off any remaining fuel before it leaves the tailpipe. The air flow/pressure sensor in this system measures the amount of air flowing through the system and ensures it is operating within the correct range.
Common Causes of P2431
- Faulty Air Flow/Pressure Sensor: The sensor itself may be malfunctioning and providing incorrect readings.
- Clogged Air Filter: A clogged air filter can restrict the flow of air through the system, leading to incorrect sensor readings.
- Leaks in the System: Any leaks in the AIR system can disrupt the flow of air and cause the sensor to detect abnormal readings.
- Malfunctioning Air Pump: The air pump may not be functioning properly, leading to issues with air injection into the exhaust system.
Symptoms of P2431
- Check Engine Light: The most common symptom associated with the P2431 code is the illumination of the check engine light on the dashboard.
- Rough Idle: The engine may experience rough idling or hesitation during acceleration due to the incorrect air flow/pressure readings.
- Decreased Fuel Efficiency: A malfunctioning Secondary Air Injection System can result in decreased fuel efficiency as the engine may not be burning fuel as efficiently.
- Increased Emissions: The vehicle may fail emissions tests or emit higher levels of pollutants due to the improper operation of the AIR system.
How to Fix P2431
- Diagnostic Testing: Use a scan tool to retrieve the DTC and perform diagnostic testing to pinpoint the exact cause of the issue.
- Inspect Air Flow/Pressure Sensor: Check the sensor for any signs of damage or malfunction and replace if necessary.
- Check Air Filter: Inspect and replace the air filter if it is clogged or dirty.
- Repair Leaks: Inspect the AIR system for any leaks and repair them to restore proper operation.
- Test System: After repairs are completed, test the Secondary Air Injection System to ensure that it is functioning correctly.
Cost to Fix P2431
The cost of repairing the P2431 code can vary depending on the specific cause of the issue and the labor rates in your area. On average, you can expect to pay anywhere from $200 to $500 for parts and labor. Keep in mind that additional costs may be incurred if more extensive repairs are needed or if other components of the AIR system require attention. It is recommended to consult with a professional mechanic to get an accurate estimate for your specific vehicle.
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Code P2431 Information for Specific Makes
- P2431 Audi — Secondary Air Injection System Air Flow/Pressure Bank 1 Sensor Circuit Range/Performance
- P2431 Buick — Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1
- P2431 Cadillac — Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1
- P2431 Chevrolet — Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1
- P2431 Dodge — Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1
- P2431 GMC — Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1
- P2431 Lexus — Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1
- P2431 Pontiac — Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1
- P2431 Saturn — Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1
- P2431 Scion — Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1
- P2431 Toyota — Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1
- P2431 Volkswagen — Secondary Air Injection System Air Flow/Pressure Bank 1 Sensor Circuit Range/Performance
Frequently Asked Questions about P2431 Code
No Frequently Asked Questions about P2431 Code found.
Discuss the causes and fixes for P2431 OBDII Code
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My 08 envoy does same thing. Replaced every part in the secondary air injection system
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The P2431 code (Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance - Bank 1) means that the airflow or pressure sensor in the Secondary Air Injection (SAI) system is reading values outside the expected range.
Since you’ve already replaced every part in the SAI system, but the code keeps coming back, here are a few things to check:
Possible Causes of P2431 Reoccurring:
- Faulty Air Injection Pressure Sensor – Even though parts were replaced, a defective or aftermarket sensor could still cause incorrect readings.
- Wiring or Connector Issue – The sensor wiring may be damaged, corroded, or loose, causing erratic signals to the ECM.
- PCM Software Update Needed – Some GM vehicles have known software issues related to the SAI system. A dealership reflash may be required.
- Exhaust Backpressure Issues – If the exhaust is restricted (partially clogged catalytic converter), it could affect airflow readings.
- Vacuum Leak or Hose Connection Issue – Double-check all hoses and fittings for cracks or improper connections.
What You Can Do:
✅ Check & Test Wiring – Inspect the air injection pressure sensor connector and wiring for corrosion, damage, or poor connections.
✅ Scan Live Data – Use an advanced scanner to monitor the air injection pressure sensor values during startup (SAI system only runs at cold start). If readings are erratic, the sensor or wiring could be at fault.
✅ Check for PCM Updates – Contact a GM dealer or check online for any ECM reflash or software updates related to the SAI system.
✅ Verify Exhaust Flow – Ensure there are no restrictions in the exhaust system that could affect airflow detection.Since your Envoy runs fine, this is likely a sensor, wiring, or PCM issue rather than a mechanical failure. If you replaced parts with aftermarket components, consider using OEM as some aftermarket sensors can cause range/performance issues.
Let us know what you find!
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So perhaps slight oversight on replacing air filter. Replaced air filter today. Old one smelled like gas probably due to Maf code and system running lean condition adding fuel by the fuel trim reading when that was a problem. P2431 code was cleared today. So far has not returned. Also cleaned mac while air filter.
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Have not replaced any parts. Had a passat turbo and the plastic hoses broke all the time from air pump. but this seem ok.
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