What Does P2431 Mean?
The secondary air injection system air flow or pressure sensor on bank 1 is providing readings outside the expected range during operation. The sensor is functioning electrically but the values don't match expected parameters.
Common Causes
35%
Weak or failing secondary air injection pump
25%
Clogged SAI pump filter or restricted air passages
20%
Leaking or stuck check valve in SAI system
10%
Exhaust leaks affecting pressure readings
10%
Degraded or out-of-calibration pressure sensor
Diagnostic Steps
1
Step 1: Command SAI pump on with scan tool and listen for pump operation and airflow
2
Step 2: Monitor pressure/flow sensor readings during SAI pump operation and compare to specifications
3
Step 3: Inspect SAI pump filter and air intake for restrictions or debris
4
Step 4: Check SAI check valves for proper operation and leaks using vacuum or pressure test
5
Step 5: Inspect exhaust connections and SAI injection points for leaks affecting pressure
Estimated Repair Cost
$200 - $800
Parts + labor, varies by vehicle and location
The secondary air injection system air flow or pressure sensor on bank 1 is providing readings outside the expected range during operation. The sensor is functioning electrically but the values don't match expected parameters.
The most common cause of P2431 (Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1) is: Weak or failing secondary air injection pump
Typical repair costs for P2431 range from $200 to $800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
No safety concern. Vehicle is safe to drive but will fail emissions testing. Only affects cold-start emissions performance.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P2431 to identify the root cause.
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Quick Info
Category
Powertrain
System
Emissions Control
Difficulty
Type
Generic (SAE)
Recommended Tools
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