Running Without the Air Pump?
 

1988 928S4, is there any harm in removing the air (smog) pump and the associated plumbing? Passing an emissions test is not a worry. I'd just like to clean up under the hood a bit........

Unless there is a problem with the air pump, I would just leave it alone. It has a filter which does need cleaning/replacement at times. If replaced, I think you would need different belts as well.

It particularly aids cold cat performance, but air injectios does help other cat performace too.

Generally the stock cats clean well enough to pass US emissions requirements without this if the engine is running right. I'm certain many cars have inoperative airpumps/diverters/vacuum actuators and the owners don't even know. Of course some states require it be there visually (most don't).

You can just cut the belt and remove, to clean up you'd have to remove the pump & its plumbing, diverter valve & vac actuator. Then cap the port to the airbox, seal off the feed port to the cats and plug the vacuum line.

Quite a lot of work to free up a little not very useful space. Unless its noisy or you need to put something in place of the pump it isn't going to change the visuals or gain performance...

Even if noisy - you could just remove the belt for the same benefit.

Alan

Thanks for the replies--the belt is already off of it, so I wanted to make sure it wouldn't hurt to be non-operational. I recently pulled the air pump system off of my 87 Corvette, which did get rid of a lot of "extra" plumbing around the engine. It does look like it would improve access to the right bank spark plugs to get rid of the diverter valve and hose, but I may just leave it for now.......