Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance - Bank 2
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.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- moderate
- Estimated cost
- $150 - $600 (parts and labor)
Best-selling code reader on Amazon. Reads and clears check engine codes on any 1996+ vehicle. Under $30.
Check Price on AmazonAffiliate link -- we earn a commission at no extra cost to you.
Essential for diagnosing sensor codes, checking voltage, and testing circuits. Under $15 and pays for itself on the first job.
Check Price on AmazonAffiliate link -- we earn a commission at no extra cost to you.
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
-
Monitor secondary air pressure sensor during cold start operation
-
Check secondary air pump output volume and pressure
-
Inspect all secondary air hoses for cracks or leaks
-
Check the one-way check valve for proper sealing
-
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.
Sources
This page is built from documented references. Verify against your own service info before repair work.
Explore More
Was this helpful?
Share carcodefinder.com with a friend who needs to decode their check engine light.