I need help getting rid of this code P0411!!!
 

The code means..(Secondary Fuel Injection System Incorret Flow Detected) and my car is 98 VW Jetta GL. I know quite alot about this cars, but this code just threw me off!! lol
I replaced the plastic tube that goes from the air pump to the EGR or Kombi valve, because it had a crack in it. I noticed the air pump blows lots of air, so the electrical part should be ok. Also, replaced the Kombi valve and most of those braided hoses with rubber ones. After a day the code comes back up.
Anyone have any ideas what could be wrong??? I will appreciate it. :)

An update. So... Today it did something weird while it was idling. The air pump came on about 3 times and it only last about less than 5 secs. each time it turned on. I've trying to figure out what it could be.
I really need help guys. Anyone???