it's very difficult (at least i haven't been able to figure it out) to accurately test the proper electrical operation of the cycle valve. there are a few ways to test via indirect means though.
1) clamp the wastegate line between the cv and the wastegate using a mini vise-grip. what this will do is keep the wastegate shut regardless if the cv is failing or not. then you can test if the motor still bogs down at full throttle.
WARNING: your boost will spike (and continue to build) so be VERY CAREFUL on the throttle or you will blow your motor during this test.
2) replace the cv with a known good one and see if the problem goes away. it's a major pain to get to the cv without removing the intake headers though, so this is a pain to do. i was actually able to do it by using a 90-degree bent allen wrench but i have not heard of anyone else who was able to with the intake headers in place.
while you're doing this, be careful you don't break/cut/crimp any of the small vacuum lines! they're usually so dried out from the heat that they're brittle.