P0410 is a generic OBDII trouble code. This means that it has the same meaning for the Subaru Impreza as it would any other vehicle. It is letting you know that there is an issue with the secondary air injection system.
P0410: Secondary Air Injection System → Malfunction
The secondary air injection system injects air into the exhaust to help lower emissions. Most of the time, P0410 is going to be caused by a failure in this pump or the one way check valve. But there can be other reasons the code is thrown as well.
P0410 Symptoms: Subaru Impreza
Nearly all of the time, the only symptom of P0410 in the Impreza is going to be the service engine soon light. Otherwise, you may hear the bad pump trying to work (like an empty wiper/washer, usually more faint sounding). Vary rarely, it can cause some hesitation on acceleration.
Impreza P0410 Causes
Typically, there are three main components to the AIR system. They are the pump, hoses, and one way check valve. All of this is electronically controlled, so checking the fuse to it is a great place to start.
Here’s a good YouTube video from Mark Jenkins on diagnosing this code:
One Way Check Valve
The most common cause of P0410 is going to be the one way check valve failing. When it does, it allows moisture into the pump. This moisture can freeze in the winter time.
If frozen water does freeze up the air pump itself, it may blow the fuse to it. This fuse is typically under the hood of the vehicle. That’s a great place to start looking. It only takes a second to see if a fuse has been blown.
AIR Pump
The AIR pump itself is the most common cause of P0410. They are relatively affordable. If they are no longer accepting instruction from the ECU, P0410 will be thrown.
Conclusion
P0410 in the Subaru Impreza is not likely to cause the vehicle to break down, and rarely causes symptoms other than the check engine light. That’s because the pump is part of the emissions system and not the engine itself. Any time the check engine light comes on, it’s a good idea to service it as soon possible though.
If there is anything that you would like to add, please leave a comment below. Good luck!