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 there is a leak in the pipe that helps blow extra air into the engine to reduce pollution. It's like having a hole in a straw when you're trying to drink a soda.
The P146C code indicates that the vehicle's computer has detected a leak in the secondary air injection system on bank 1, which is the side of the engine with cylinder 1.
The secondary air injection system is used to inject air into the exhaust stream to help reduce emissions. A leak in this system can cause incorrect air-fuel ratios, leading to increased emissions and potential engine performance issues.
• Check engine light on
• Increased emissions
• Possible engine performance issues
• Damaged or cracked air injection hose
• Faulty air injection pump
• Leaking air injection valve
Secondary Air Injection: A system that injects air into the exhaust stream to help reduce emissions.
Bank 1: The side of the engine that contains cylinder 1.
• Inspect the secondary air injection hoses for damage or leaks.
• Check the operation of the air injection pump.
• Test the air injection valves for proper sealing.
• Replace damaged air injection hose.
• Repair or replace the air injection pump.
• Replace faulty air injection valve.
• OBD-II scanner
• Vacuum gauge
• Basic hand tools
$100 - $500
Moderate
• BMW 3 Series
• Mercedes-Benz C-Class
• Audi A4
• Regularly inspect and maintain air injection system components.
• Ensure hoses and connections are secure and free from damage.
• Perform routine emissions system checks.
Emissions Control
• Address this issue promptly to avoid increased emissions.
• Consult a professional mechanic if unsure about repairs.
Check with the vehicle manufacturer for emissions-related warranty coverage.
This code is commonly associated with vehicles that have secondary air injection systems, particularly in models with stringent emissions standards.
Moderate – While not immediately critical, addressing this issue helps maintain emissions compliance and engine performance.
Ignoring emissions-related issues can lead to failing emissions tests and potential fines in regions with strict emissions laws.
• Engine at operating temperature
• System under load
The secondary air injection components are typically located near the front of the engine bay, close to the exhaust manifold on bank 1.
Q: Can I drive with a P146C code?
A: While you can drive with this code, it's best to fix it soon to avoid increased emissions and potential performance issues.
Q: How can I prevent a P146C code?
A: Regular maintenance and inspection of the air injection system can help prevent leaks and related issues.
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