Is the air pump clutch supposed to disengage once the car goes above idle?

I'm trying to plumb an airline from the pump to the cat to see if I can get it to pass emmissions, but if the pump disengages above idle, then it won't do me any good.

Also, my air pump isn't pulling vacuum at idle at the intake filter.

Does the pump maybe remain engaged only when the engine is under a load allowing it to pull vacuum at the pumps intake at higher RPM's?

Please help.

Thanks

 

The pump cuts out somewhere around 3000 RPM I believe.

 

Is there any way to keep it engaged? or would it hurt me even more by keeping that load on the engine while trying to pass emissions on the dyno. I was 4 times the limit the first time I went.

 

I take it back, there is vacuum at idle, but I don't know enough to know what the air pump is for. Would it be a bad thing to temporarily remove the existing line that is attached to the back side of the engine and run it down to the cat to get through emissions? Or do I need to put a tee in there so both can be connected?