P2448 - Secondary Air Injection System High Air Flow Bank 1
The P2448 code indicates that the Powertrain Control Module (PCM) has detected excessive air flow in the secondary air injection system on Bank 1. This system pumps fresh air into the exhaust to reduce emissions during cold starts. High air flow can be caused by a stuck-open secondary air injection shutoff valve, a faulty air pump relay, or a leaking air hose. The PCM monitors air flow via the oxygen sensors and will set this code if the air flow exceeds a calibrated threshold.
01. Most Common Causes
- Stuck-open secondary air injection shutoff valve
- Faulty secondary air injection pump relay
- Leaking or disconnected air injection hose
- Failed secondary air injection pump (running continuously)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Failed emissions test
- Possible rough idle or hesitation on cold start
- Unusual noise from air pump area
03. Step-by-Step Diagnosis
Step 1: Scan for codes and verify P2448 is present. Check freeze frame data.
Step 2: Visually inspect secondary air injection hoses and connections for leaks or damage.
Step 3: Test the secondary air injection shutoff valve operation using a vacuum pump or scan tool.
Step 4: Check the air pump relay and fuse; listen for pump operation during cold start.
Step 5: Use a smoke machine to detect vacuum leaks in the air injection system.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
Yes, but the vehicle may fail an emissions test and the Check Engine Light will remain on. It's best to repair promptly to avoid further issues.
How much does it cost to fix?▼
Typical repair costs range from $50 to $150 for parts like a relay or hose, but if the shutoff valve or pump needs replacement, costs can be higher.