Cause
Failed secondary air check valve
The one-way valve stopping exhaust gas backing into the air pump. It fails first and the pump is what gets replaced — a new pump behind a failed valve is cooked the same way, and the valve costs a fraction of it.
Typically a moderate job.
Codes this can cause (10)
Codes where this is a likely explanation first, rather than merely a possible one.
- P2257 Secondary Air Injection System Control A Circuit Low Likely for this code Moderate
- P2431 Secondary Air Injection System Air Flow Pressure Sensor Circuit Range/Performance Bank 1 Likely for this code Moderate
- P2435 Secondary Air Injection System Air Flow Pressure Sensor Circuit Bank 2 Likely for this code Moderate
- P2436 Secondary Air Injection System Air Flow Pressure Sensor Circuit Range/Performance Bank 2 Likely for this code Moderate
- P2440 Secondary Air Injection System Switching Valve Stuck Open Bank 1 Likely for this code High
- P2442 Secondary Air Injection System Switching Valve Stuck Open Bank 2 Likely for this code High
- P2445 Secondary Air Injection System Pump Stuck Off Bank 1 Likely for this code Moderate
- P2447 Secondary Air Injection System Pump Stuck Off Bank 2 Likely for this code Moderate
- P2259 Secondary Air Injection System Control B Circuit Low Moderate
- P2430 Secondary Air Injection System Air Flow Pressure Sensor Circuit Bank 1 Moderate
Information, not instruction
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