Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance - Bank 2
What does P2431 mean?
The P2431 code means the vehicle's onboard diagnostic system has detected: Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance - Bank 2. This is a low severity code.
Common Symptoms
- Check Engine Light illuminated
- Failed emissions inspection
- Secondary air system not performing correctly
- No drivability concerns
- Cold start emissions higher than normal
Probable Causes (Ranked by Likelihood)
- Degraded secondary air pressure sensor Very High
- Partially clogged secondary air passages High
- Weak secondary air pump not producing enough flow Moderate
- Air leak in secondary air injection hoses Moderate
Step-by-Step Diagnostic Procedure
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Monitor secondary air pressure sensor during cold start operation
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Check secondary air pump output volume and pressure
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Inspect all secondary air hoses for cracks or leaks
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Check the one-way check valve for proper sealing
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Inspect exhaust manifold air injection ports for carbon buildup
Frequently Asked Questions
Can I drive with code P2431?
Yes, safe to drive. The secondary air injection only affects cold start emissions and does not impact driving performance.
What causes P2431?
Usually a degraded pressure sensor or partially clogged air injection passages. A weak air pump that is wearing out can also cause insufficient airflow.
Is P2431 expensive to fix?
Typically $150 to $600. Start with the sensor and check valves. Air pump replacement is more expensive but less commonly needed.