There is a line that goes to the bottom of the LIM, which connects to two banjo bolts on the bottom left and the bottom right side of the LIM. Backtracing, it connected to metal hose.

What are these two hoses intended to do? Unfortunately, I did not mark them, assuming it was part of rat's nest removal due to the metal hose.

 

To be clear, the entire run is metal pipe.

It connects to the two "weirdly shaped" holes directly under the first/second/third/fourth ports on the engine.

I think this is for the EGR valve, specific to S4 engines? Can it be safely blocked off if so, if the EGR valve is being removed? Whatever it does, it takes exhaust from the engine, and I have no idea what it is specifically for now that the damn vacuum tube routing is gone.

 

It sounds like you're talking about the line that sends pressure to the auxiliary port actuators. It is supposed to be connected to the split air pipe, so exhaust pressure can open the ports at 3800 rpm. If it is hooked to nothing, then your ports will never open, and you'll be down ~25 hp.

More info here: http://mazdarx7.iougs.com/intakeair.shtml

Make sure you still have the actual actuators too. Lazy people have a habit of removing them and wiring the ports permanently open.

 

sounds like the pressure tubing for the 6 port actuators.
remember they are actuated by exhaust.
the exhaust exits the block, goes back through the LIM then up to that "top" metal hose, which connects to a hose that runs to the main cat a.k.a. split air pipe.
there is a small tube that runs off of that hose to the metal frame that is bolted to the LIM by those two banjo bolts you described.

Hope that helped
-Pat

 

Decided to take pictures.





This is the pressure tubing?

 

yeah it goes to the hole under the bolt that goes to your actuator.

 

Thank you. Ends up after looking at many pictures, the old owner didn't even have it hooked up.

That's why I couldn't figure out what it was, and after reading through entire sections on the FSM, although it shows it in diagrams, it never actually identifies it .