P2433 - Secondary Air Injection System Air Flow/Pressure Sensor Circuit High Bank 1
The P2433 code indicates that the Powertrain Control Module (PCM) has detected a high voltage signal from the secondary air injection (SAI) system air flow/pressure sensor on Bank 1. This sensor monitors the air flow or pressure in the SAI system, which pumps fresh air into the exhaust to reduce emissions during cold starts. A high voltage reading typically means the sensor is reading excessive pressure or flow, or there is a short to voltage in the circuit. Common causes include a faulty sensor, wiring issues, a stuck-open SAI pump relay, or a blocked SAI system.
01. Most Common Causes
- Faulty secondary air injection pressure sensor
- Short to voltage in sensor wiring or connector
- Stuck-open SAI pump relay
- Blocked or restricted SAI system passages
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Failed emissions test
- Possible rough idle or hesitation on cold start
03. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve freeze frame data and verify the code.
Step 2: Inspect the SAI pressure sensor and wiring for damage, corrosion, or shorts.
Step 3: Test the sensor voltage signal with a multimeter; compare to manufacturer specs.
Step 4: Check the SAI pump relay and fuse for proper operation.
Step 5: Inspect the SAI system hoses and passages for blockages or leaks.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is generally safe to drive short distances, but the vehicle may fail an emissions test and the Check Engine Light will remain on. Prolonged driving could lead to reduced performance or damage to the SAI system.
How much does it cost to fix?▼
Repair costs typically range from $50 to $150 for parts and labor, depending on the cause. A sensor replacement is usually around $100, while wiring repairs may be less.