I have an s4 I have replace the exhaust and due to emission laws my car no longer needs an e-test. If I cannot just hook the tube that went to the cat to the the piping where the cat used to be How can I get them to open and close.

 

There is a method that involves tapping a hos off of the airpump to get them to open at the right time. Check the archives, the original thread explains it better than I ever could.

If you are going to be getting rid of the emissions stuff though, you will have to open them electronically. Here's a writeup. I would like to point out that even before you consider doing the sytem that way, you should consider the risks of wiring things up using existing connectors. It has been working fine for me, but if something goes wrong with the system it can possibly cause a lot of damage to the electrical system. The preferred way to do it is to run power wires directly to the battery.

http://www.teamfc3s.org/forum/showth...threadid=42367