I just did this on a Saabaru last night.
The sensor needs to be preloaded as quazimoto said.
To preload the spring you need to attach the sensor to the peg on the end of the TGV axle WITH THE ELECTRICAL CONNECTOR FACING UP then rotate a little greater than 90 degrees clockwise untill its in its position to be bolted down. Then screw it down and plug it back in.
It seems like if that sensor isn't working, the TGVs stay closed all the time. If the TGVs stay closed all the time that bank doesn't get any air or fuel.
Since your primary O2 is on the other bank, it never makes any AFR corrections based on it as it doesn't realize this. If you take this to its natural conclusion you get tons of #2 and #4 misfires, can't build full boost. Car feels slow, sounds funny, won't idle, etc.