Heyy! Welcome to the forum! Good luck figuring out everything...

BTW thanks for the pic up there of all of the pulleys! Very helpful to have something like that on file

I am also having a low boost problem. the computer tells me its the bypass solenoid. I went out and revved it up and the arm does move. Does anyone know what i need? the solenoid or bypass valve or both? THANKS

I'm frustrated and in my search I found a image of broken idle pulley as it looks on my sons 99 grand prix.... I read he got it off turning it counter clock wise. Where was bolt? Had it been broken off or was it completely gone. I haven't seen if a bit of bolt is in there but what I felt didn't seen to be in there. Been having a hard time finding bolt and spacer, going to junk yard tomorrow hoping to get one there. I hope original guy gets this, or someone who knows how I can get this old broken piece off. Thank u so much

I believe it is a torx head bolt, located on the outboard side (toward the right fender) of the pulley, removed by turning CCW.

Thanks 2kg4u, but found that *** that was left actually the dome shape is the bolt... took some effort to get off but mission accomplished