Hate to beat a dead horse but I still have some confusion, I have a 87 N/A and recently changed out my auto for a 5 speed. while I was doing this The catalyst seemed to fall out of the exhaust with a little help. I disconnected the tube that runs from the manafold and plugged both ends. Now my question is do need that tube to open the ports, or by plugging that tube give me the back presure I need to open them from the air pump. Or can I remove the air pump - take the check out of the tube from the maniforld to the exhaust line or give me back pressure to open the ports.

 

Since you have an s4 the aux ports are opened by backpressure. I would say general concensus is that if you still have the stock exhaust with gutted cats your ports should still open up fine.

You can do a search on 'full blown electrical auxillery port activation" or somehting like that. I think it's in the archive.