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 the car's computer is having trouble measuring the air flow or pressure in a part of the engine that helps reduce pollution. It's like trying to breathe through a straw that's blocked.
The code P2431 indicates a problem with the secondary air injection system's air flow or pressure sensor in bank 1. The sensor is not sending the expected signals to the engine control module (ECM).
The P2431 code is triggered when the ECM detects a range or performance problem in the air flow or pressure sensor circuit of the secondary air injection system for bank 1. This system is responsible for injecting air into the exhaust stream to reduce emissions. The sensor's readings are outside the expected range, indicating a potential fault in the sensor or its circuit.
• Check Engine Light is on
• Poor engine performance
• Increased emissions
• Faulty air flow/pressure sensor
• Damaged or corroded wiring or connectors
• Faulty ECM
ECM: Engine Control Module
OBD-II: On-Board Diagnostics II
• Use an OBD-II scanner to confirm the code.
• Inspect the air flow/pressure sensor and its wiring for damage.
• Test the sensor with a multimeter to ensure it is functioning properly.
• Replace the faulty air flow/pressure sensor.
• Repair or replace damaged wiring or connectors.
• Reprogram or replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $400
Moderate
• Toyota Camry
• Lexus RX350
• Chevrolet Silverado
• Regular maintenance of the air injection system.
• Ensure wiring and connectors are clean and secure.
• Use high-quality fuel to reduce carbon buildup.
Sensor Issue
• Do not ignore the Check Engine Light.
• Have your vehicle inspected by a professional mechanic.
• Avoid driving the vehicle excessively until repaired.
Check with your vehicle manufacturer for specific warranty coverage on emissions-related components.
The P2431 code has been commonly reported in vehicles with secondary air injection systems, particularly in models with higher mileage.
Moderate – While the vehicle may still be drivable, it is important to address this issue to maintain performance and emissions standards.
Driving with a malfunctioning emissions system may violate emissions regulations and contribute to environmental pollution.
• Engine at operating temperature
• Secondary air injection system active
The air flow/pressure sensor is typically located near the secondary air injection pump or in the air injection system's piping.
Q: Can I drive with a P2431 code?
A: While you may be able to drive, it is not recommended as it can lead to increased emissions and potential engine performance issues.
Q: How can I prevent a P2431 code?
A: Regular maintenance and inspections of the air injection system can help prevent this code.
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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 for airflow, fuel-trim, and intake-metering faults after confirming the sensor is actually at fault.
Airflow and fuel-trim codes can involve the mass air flow sensor after proper diagnosis.
Verify the sensor design and fitment for your exact vehicle.
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.