I have searched the archives but cannot find a description on how the aux ports are activated. I have a 88 n/a. Looking at the tubing lines that go from a T on the split pipe to the converter it goes to one of the actuators and then T's into the block and comes out again at the other actuator for the aux port. As I see it the air pump is opening the actuators. so, there must be a solenoid that opens and closes a valve in the air control valve. Is this where the exhaust back pressure is needed to operate this valve? I assume that this means that the cat is not always getting a flow of air. Also, should the actuators for the aux valves move to the extent that the bell crank on the valve moves 180 degrees?

 

It's all exhaust backpressure- or lack thereof- If you have the stock exhaust, you should be ok for now, unless they're stuck...Once you start modifying the exhaust (hi-flow cat, nice cat-back), you'll have to find an alternate air source...

Yes, the rod should bury itself into the actuator when fully pressurized...

 

Either searching is highly inefficient, or you didn't look very hard.

S4: backpressure
S5: ECU, Solenoids, Air pump

I've got a video in another thread of the aux actuators opening...