So, I'm sure this is very obvious to some of you, but bear with me. I have consulted the Haynes Manual, and it only has the S5 exhaust diagram for some reason.



I have an S4 and it has a catback, and I don't see any new hookups for the backpressure tube on the main cat, so I'm guessing that my aux ports aren't even working...which sucks.



This is my exhaust manifold (which I hope to be rid of soon) and the various tubes and hoses that are floating around. I arrowed the one that I believe would be the actuator hose, but I just want to confirm before I start trying to fix it.

 

You're definitely missing the hose that's supposed to connect to the exhaust, but it's much larger than the one you've pointed to.

 

Well crap.. I guess that's not surprising though. I investigated further, and used some spare hose I had around and ran some compressed air (i.e. used lung power) to the arrowed hose; and it actually moved the actuators. So it's the wrong size hose, but at least they work...



Since I do want to go with headers at some point it seems that my choices are:

1. Buy a header that has the 5th/6th port hookup and be done.

2. Buy a new main cat that has hookup and then get a header.



From what I can find, Racing Beat is the only company that makes a header with the aux port tube, and I'm wary of that because it's a true dual setup, and I'm currently running a single outlet. So I don't know how much work it would be to make it function.



Other plan would be buy a new magnaflow with the aux tube and then get a cheaper header. There are some on ebay that look like they are made of some nice thick steel that won't get torched by the rotary or rust away. Though, I am in Texas, and rust doesn't seem to be as much of a problem here.



I appreciate the advice I get here. This really is a great resource.

 

Originally there was a larger tube that ran from the main cat to the (I think) ACV, that had a small vacuum nipple on it where your arrow'd tube connected. I'm not sure how all that works, but if you're keeping your emissions, you might need that, I really don't know (hopefully someone else will chime in here).

 

Okay, sounds like it will be simple enough to remedy. I should be able to swing by an exhaust shop tomorrow, or the day after, and see how much it's going to run me to get work done.



Also if anyone actually knows, or perhaps better yet has a picture they are willing to share of the proper setup for the aux port system; I will be in your debt.

 

Just have them weld in a section of maybe 3/8th inch pipe before the cat and run a hose to the actuator hard line.

 

So this is essentially what it would look like? (mad artistic skills)



The metal tube from the exhaust would run as far back as possible I assume? I can't imagine hoses being able to withstand much heat from the exhaust.

 

that is 100% correct. I would take off the lower intake manifold and clean out the sleeves to make sure there range of travel is free of gunk and stuff for smooth trouble free operation. I could blow into the vac line and make the actuators open after lubing and cleaning them.

 

Sweet! I can't wait to see what my FC is really capable of with the handicap removed. And I will definitely take everything apart and clean them out. Would suck to have it all hooked up but still not work because I was lazy.

 

You can run a vac line from the airpump to the actuator just tap into the large hose on the back of the pump.