Secondary Air Injection System Flow/Pressure Sensor Performance Bank 1
The P2431 code indicates that the Engine Control Module (ECM) has detected a performance or range issue with the secondary air injection system pressure sensor on Bank 1. This system injects air into the exhaust to reduce emissions during cold starts. The sensor monitors air flow/pressure; when its signal is outside expected parameters, the code sets. Common causes include a faulty sensor, wiring issues, or a blocked air injection pump or hoses.
01. Most Common Causes
- Faulty secondary air injection pressure sensor
- Wiring or connector issues in the sensor circuit
- Blocked or leaking secondary air injection hoses
- Malfunctioning secondary air injection pump
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Failed emissions test
- Possible rough idle or hesitation on cold start
- Reduced engine performance
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect the secondary air injection system hoses and pump for damage or blockages.
Step 3: Test the pressure sensor signal voltage with a multimeter and compare to specifications.
Step 4: Check wiring and connectors for corrosion, shorts, or opens.
Step 5: If sensor and wiring are okay, test the air injection pump operation.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
Yes, but it may cause increased emissions and could fail an emissions test. It's best to repair promptly to avoid potential catalytic converter damage.
How much does it cost to fix?▼
Repair costs vary from $150 to $400, depending on the cause. A sensor replacement is typically $100-$200, while pump replacement can be $200-$400.