Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means there's a problem with the system that helps reduce pollution from your car. It's like a helper system that blows extra air into the engine to make it cleaner, and it's not working right on one side of the engine.
The secondary air injection system helps reduce emissions by injecting air into the exhaust stream. This code indicates that the sensor monitoring this system's air flow or pressure is not reading correctly on Bank 2.
The P145B code is triggered when the Engine Control Module (ECM) detects that the air flow or pressure sensor in the secondary air injection system is out of range during initialization on Bank 2. This could be due to a faulty sensor, wiring issues, or a malfunctioning air pump.
• Check Engine Light is on
• Poor engine performance
• Failed emissions test
• Unusual noises from the engine
• Faulty air flow/pressure sensor
• Wiring or connector issues
• Malfunctioning secondary air injection pump
• Blocked or leaking air injection hose
• Faulty ECM
ECM: Engine Control Module
Bank 2: The side of the engine opposite Bank 1, typically the side without cylinder 1
Secondary Air Injection System: A system that injects air into the exhaust to help reduce emissions
• Use a diagnostic scanner to confirm the code
• Inspect the air injection system components for damage
• Test the air flow/pressure sensor
• Check wiring and connectors for continuity and damage
• Inspect the air pump for proper operation
• Replace the faulty air flow/pressure sensor
• Repair or replace damaged wiring or connectors
• Replace or repair the secondary air injection pump
• Clear any blockages in the air injection hose
• Reprogram or replace the ECM if necessary
• OBD-II scanner
• Multimeter
• Wrench set
• Screwdriver set
• Air pressure gauge
$150 - $600
Moderate
• BMW 3 Series
• Mercedes-Benz C-Class
• Audi A4
• Regular maintenance of the air injection system
• Timely replacement of faulty sensors
• Regular inspection of wiring and connectors
Sensor Issue
• Address this issue promptly to avoid failing emissions tests.
• Consult a professional mechanic for accurate diagnosis.
• Avoid driving extensively with this code active to prevent further damage.
Check with your vehicle manufacturer for warranty coverage on emissions-related components.
This code has been known to appear in vehicles with aging secondary air injection systems, especially in models over 5 years old.
Moderate – Addressing this code is important for emissions compliance and engine performance.
Driving with a malfunctioning secondary air injection system may result in failing emissions tests and increased pollution.
• Engine at operating temperature
• Vehicle in idle or low load conditions
The secondary air injection system components are typically located near the front of the engine bay, close to the exhaust manifold.
Q: Can I drive my car with a P145B code?
A: While you can drive with this code, it is not recommended as it may lead to increased emissions and potential engine performance issues.
Q: What happens if I ignore the P145B code?
A: Ignoring this code can result in failing emissions tests and may lead to further engine problems over time.
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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.