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 has detected a problem with the air pressure sensor in the secondary air injection system on one side of the engine. It's like when you blow air into a balloon and a sensor is supposed to check how much air is going in, but it's reading too high.
The P2438 code is triggered when the Engine Control Module (ECM) detects a high voltage signal from the air flow/pressure sensor in the secondary air injection system on bank 2.
The secondary air injection system is designed to reduce emissions by injecting air into the exhaust system to promote the oxidation of hydrocarbons and carbon monoxide. The air flow/pressure sensor monitors the amount of air being injected. A 'high' circuit signal indicates that the sensor is reporting more air flow or pressure than expected.
• Check Engine Light illuminated
• Poor engine performance
• Increased emissions
• Rough idle
• Faulty air flow/pressure sensor
• Wiring issues such as shorts or open circuits
• Faulty secondary air injection pump
• Blocked or restricted air passages
ECM: Engine Control Module
OBD-II: On-Board Diagnostics II
Bank 2: The side of the engine opposite to bank 1, usually the side without cylinder 1
• Use an OBD-II scanner to confirm the P2438 code.
• Inspect the wiring and connectors related to the air flow/pressure sensor.
• Test the air flow/pressure sensor for proper operation.
• Check the secondary air injection pump for functionality.
• Repair or replace damaged wiring or connectors.
• Replace the faulty air flow/pressure sensor.
• Clean or replace blocked air passages.
• Replace the secondary air injection pump if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools (screwdrivers, wrenches)
$150 - $400
Moderate
• Toyota Camry
• Lexus RX350
• Chevrolet Silverado
• Regular maintenance of air injection system
• Periodic inspection of wiring and connectors
• Ensure air passages are clear of debris
Sensor Issue
• Do not ignore the Check Engine Light; have it diagnosed promptly.
• Regularly maintain the vehicle's emission system.
• Seek professional help if unsure about repairs.
Check with the vehicle manufacturer for warranty coverage on emission-related components.
The P2438 code has been more common in vehicles with aging emission systems, particularly those with secondary air injection systems.
Moderate – While the vehicle may still be drivable, it can lead to increased emissions and potential engine performance issues.
Driving with a malfunctioning emission system may violate emission laws and contribute to environmental pollution.
• Engine at operating temperature
• Secondary air injection system activated
The air flow/pressure sensor is typically located near the secondary air injection pump on bank 2 of the engine.
Q: Can I drive with a P2438 code?
A: While you can drive with this code, it's not recommended as it can lead to increased emissions and potential engine issues.
Q: How do I clear a P2438 code?
A: After repairs, you can clear the code using an OBD-II scanner, but ensure the issue is resolved to prevent it from returning.
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Universal · Digital multimeter
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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.