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 noticed a problem with the air system that helps clean the car's exhaust. It found that the air pressure was different when the car was driven twice.
The P145D code is triggered when the vehicle's computer detects a discrepancy in the air flow or pressure sensor readings of the secondary air injection system between two driving cycles for Bank 2.
The secondary air injection system is designed to reduce emissions by injecting fresh air into the exhaust stream. The air flow/pressure sensor monitors the performance of this system. If the sensor detects a significant difference in pressure between two consecutive driving cycles, it triggers the P145D code, indicating a potential fault in the system or sensor.
• Check Engine Light is on
• Failed emissions test
• Poor engine performance
• Unusual noises from the air injection system
• Faulty air flow/pressure sensor
• Leaks in the secondary air injection system
• Blocked or restricted air lines
• Faulty secondary air injection pump
• Wiring issues or poor electrical connections
Secondary Air Injection System: A system that injects fresh air into the exhaust stream to help reduce emissions.
Bank 2: The side of the engine opposite to Bank 1, typically referring to the side without cylinder 1.
• Use an OBD-II scanner to confirm the P145D code.
• Inspect the secondary air injection system for leaks or blockages.
• Test the air flow/pressure sensor for proper operation.
• Check the wiring and electrical connections related to the sensor.
• Replace the faulty air flow/pressure sensor.
• Repair any leaks in the secondary air injection system.
• Clear any blockages in the air lines.
• Replace the secondary air injection pump if necessary.
• OBD-II scanner
• Multimeter
• Vacuum gauge
• Basic hand tools
$150 - $500
Moderate
• BMW 3 Series
• Mercedes-Benz C-Class
• Audi A4
• Regular maintenance of the secondary air injection system
• Timely replacement of faulty sensors
• Ensure proper electrical connections
Sensor Issue
• Have the vehicle inspected by a professional mechanic.
• Avoid driving the vehicle extensively until the issue is resolved.
Check with the vehicle manufacturer for specific warranty coverage related to emissions systems.
This code has been more prevalent in vehicles with aging secondary air injection systems, particularly in models from the early 2000s.
Moderate – While the vehicle may still be drivable, it can lead to increased emissions and potential engine performance issues.
Driving with a malfunctioning emissions system may not only be illegal in some areas but can also lead to increased pollution.
• Engine at operating temperature
• Vehicle driven in varied conditions
The air flow/pressure sensor is typically located near the secondary air injection pump or along the air lines leading to the exhaust manifold.
Q: Can I drive with a P145D code?
A: While you might be able to drive with this code, it's best to fix it soon to avoid increased emissions and potential engine issues.
Q: What happens if I ignore the P145D code?
A: Ignoring this code can lead to failed emissions tests, reduced engine performance, and possible damage to the secondary air injection system.
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A wired color-screen reader with readiness hotkeys, live data, code definitions, and data logging.
Good for emissions-related codes because it exposes readiness monitors and live powertrain data.
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Specialty · Smoke machine
Helpful for finding EVAP and vacuum leaks that are hard to see with visual inspection alone.
Helpful for tracking down EVAP and vacuum leaks that can trigger emissions faults.
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Specialty · O2 sensor socket
Helpful when the code points toward exhaust or oxygen-sensor work and space is tight.
Useful when the diagnosis points toward oxygen-sensor removal or replacement.
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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.