High NOX

[Nickster]

I have a V90 with high NOX numbers. I'm not getting any OBDII codes about air injection, but since I've not found any cracked vacuum lines, I thought I would check the air injection system anyway (knowing that the OBDII implementation for these models is half-baked).

Anyway, after testing the air pump and the check valve (both good), I noticed that there is vacuum in the line going to the solenoid valve but almost none coming out of it (at 1,500 RPM), so I am beginning to suspect this baby. Is my testing procedure OK or is there a better way to test the solenoid?

Thanks