The air pump ( i believe ) that is attached to the stock air box via a hose.

I disconnected that when i took my airbox out, but now it is just sucking air from the engine bay.

Is that what it is supposed to be doing?

My airpump line isn't attached to the exhaust anyhow, as i have no cat.

Can i just leave it hanging there?

 

No...you want to get a little filter to put on there.

-Joe

 

arg, what are they called?

and will i be fine to drive a few km to the local auto shop?

 

if your air pump isn't attached to anything you can leave it hanging there. but i recommend you just take the whole pump assembly off.

 

You do NOT need a filter if it's not going to anything.

If you have no cat, just leave it hanging there, or do the better thing and just take it out.

 

Wait, you have an s5 so the airpump controls the VDI and Aux ports, you may want a filter then.

 

The air pump needs a filter if it is still connected to the ACV. It blows air into the rear rotor during decel. So it needs to be filtered.

But once you remove the cats (and assuming it's an S4 NA or a TII) you might as well remove the ACV and air pump.

 

Until you're ready to set up an electric pump to work the aux ports & VDI, just put a small filter on the pump intake.

 

That air goes to about 5 solenoids + aux port actuators if its an n/a. You don't want to be shoving dirt into any of those. Unless you removed all of that, and you're only keeping hte air pump for sake of keepin the secondary water pump belt, keep it filtered.

Otherwise ditch it and get a secondary aternator pulley