My friends wrx threw a code (p0410) secondary air valve? I've done a little research and it seems that it can be a pain. Is a system delete a smart possibility?

No delete if it gets emission testing. I'd investigate what went wrong and repair.

there's a long thread about the issue at NASIOC.

 

I used RomRaider and ECU flash to kill 14 codes on my 06 . both valves are stuck closed and have been for years. There are still in place but I pulled a fuse and a relay.  No issue with emissions testing. (folks with valves stuck open have more work to do.) Your 07 needs to have a sensor divorced from one of the valves if you remove it. There's no evidence Subaru improved the replacement s parts and they are expensive.

 

read here; http://forums.nasioc.com/forums/showthread.php?t=1209260

Just to add to the above, RomRaider and ECUFlash are both free software you can download and run on most Windows-based laptops. You need a special Tactrix cable to connect  to the car's OBD2 port.

 

In this case, find someone local that does tuning and they can turn off the code.. Don't expect it be free, but likely much cheaper than trying to fix one of Subaru's design mistakes from the factory.

 

td