P0492 indicates the secondary air injection system on bank 2 is not delivering enough airflow during cold-start operation. The system injects fresh air into the exhaust stream to accelerate catalyst light-off; insufficient flow means the catalyst may not reach optimal temperature quickly enough, increasing emissions.
The electric or belt-driven pump may be seized, worn, or producing low output, preventing adequate airflow.
A check valve that fails to open fully or leaks exhaust back-pressure blocks flow into the exhaust manifold.
Cracked, disconnected, or deteriorated hoses between the pump, solenoid, and check valve reduce delivered airflow.
An electrical fault in the solenoid that routes vacuum/pressure to the check valve, or its control relay, can prevent system activation.
Open circuits, short circuits, or corroded terminals in the pump or solenoid control circuits interrupt command signals.
Internal driver failure or software logic error in the control module is possible but uncommon; verify all other causes first.
The vehicle is usually drivable, but cold-start emissions will be higher and the vehicle will likely fail an emissions inspection. Extended operation does not typically cause engine damage.
Yes, the terms are often used interchangeably; it is an emissions-control device that supplies fresh air to the exhaust during cold starts.
PCM failure is a very rare cause. The code is almost always due to a mechanical pump, valve, hose, or wiring fault. Replace the PCM only after all other components have been verified functional.
If the underlying flow restriction or component fault is not repaired, the code will return once the monitor runs again, typically on the next cold start.