The P2440 code indicates that the secondary air injection switching valve on Bank 1 is mechanically or electrically stuck in the open position. This causes excess air to be continually injected into the exhaust stream, which can lead to high oxygen sensor readings, catalyst inefficiency, and illumination of the malfunction indicator lamp.
The valve’s internal components (spring, diaphragm, or flapper) can seize or break, keeping the valve permanently open.
A damaged, disconnected, or clogged vacuum hose can prevent the valve from actuating to the closed position.
An open or shorted solenoid, corroded connector, or damaged harness can lock the valve in the open state.
Abnormally high pressure from the pump can hold the valve open or cause it to fail in the open position.
Rarely, the Powertrain Control Module may command the valve incorrectly or misinterpret the position signal; this should be the last cause considered.
No. In the vast majority of cases the problem lies in the valve itself, its vacuum supply, or the electrical circuit. PCM replacement should only be considered after all other causes have been ruled out.
The vehicle may run, but prolonged operation with excess air entering the exhaust can damage the catalytic converter and cause poor driveability. It is advisable to repair the issue promptly.
If the valve is stuck due to carbon buildup, cleaning may temporarily restore movement, but a mechanically failed valve typically requires replacement for a lasting fix.
Yes. An air pump that produces excessive pressure or allows back‑flow can keep the switching valve open, although this is less common than a direct valve or control‑line failure.