HomeTrouble CodesP2448

P2448 — Air System High Air Flow Bank 1

Manufacturer-specificPowertrain (engine & transmission)

This code indicates that the engine computer has detected an unusually high volume of air flowing through the secondary air injection system on Bank 1. This system pumps extra air into the exhaust during cold starts to reduce emissions, and excessive airflow usually points to a mechanical or electrical fault allowing air or current to flow unchecked.

Symptoms

What causes it — most likely first

1. Stuck open air injection check valve

The mechanical valve that directs air into the exhaust can stick open, allowing continuous airflow instead of closing when the system turns off.

2. Shorted air injection pump relay

If the relay that controls the pump shorts closed, it will supply continuous power to the pump, causing it to run and force air into the system when it should be off.

3. Wiring harness short to voltage

A short in the wiring to the air injection pump or solenoid can cause the components to operate continuously, triggering the high flow condition.

4. Faulty air injection pressure sensor

The sensor that monitors airflow might report erroneously high readings if it has failed or is reading inaccurately due to moisture or carbon contamination.

5. Engine computer (PCM/ECM) failure

Extremely rare, but the engine computer could internally short and command the secondary air system on continuously.

How it's diagnosed

  1. Scan for all codes and document freeze frame data to see under what conditions the fault occurs.
  2. Inspect the secondary air injection system wiring, connectors, and relay for signs of damage, corrosion, or a short to voltage.
  3. Test the air injection check valve on Bank 1 to ensure it opens and closes properly and is not stuck open due to carbon buildup.
  4. Check the air injection pump relay operation; verify it is not sticking closed and supplying constant battery voltage to the pump.
  5. Monitor the air injection pressure sensor data with a scan tool to see if the readings are plausible or if the sensor is reporting high flow incorrectly.

Code facts & related codes

SystemPowertrain (engine & transmission)
StandardizationManufacturer-specific (P1/B1/C1/U1)

Frequently asked

Can I drive my car with a P2448 code?

You can usually drive it short-term, but the secondary air pump running continuously can drain the battery, overheat the pump, or cause a rough idle. It should be diagnosed soon.

Does P2448 mean my secondary air pump is bad?

Not necessarily. Because the code is for *high* airflow, the pump is likely working too well because it is running when it should not be, or the valve directing the air is stuck open.

My mechanic said I need a new engine computer for this code, is that right?

Probably not. Replacing the PCM/ECM for a P2448 code is almost always a misdiagnosis. The root cause is almost always a stuck relay, stuck check valve, or wiring issue.

Why does the air pump keep running after I shut off the engine?

This is usually caused by a stuck closed (shorted) air injection pump relay, which keeps supplying battery power to the pump even when the ignition is off.