Exhaust question
 

I was reading in another post that the tube that runs in to the main cat has to be hooked up but I do not have a cat can I just put it on the exhaust tube?

i dont see why not? so you will just have straight pipe back without cats right?

well what you can do is just wire open your aux ports. that is what that tube is for is to open your aux ports. so if you wire open you aux ports you wont need that tube

Not true. That is the split air pipe that feeds air into the cat to get it heated up, it has nothing to do with aux. port operation. If you dont have a cat, you can just hack it off or remove it from the back of the lower intake.

So there should not be a problem if I do that and it will work properly

ahh then i was told wrong... damn false information

im thinkin that this shouldnt be a problem. theres gonna be less restriction=hp gain, and your car will be louder, YAY! but i wouldnt be the person to ask. i dont know rotaries well at all. i know subaru's lol im new to the rotary cars.

thats right i did the same thing as you. took my cat out and i hacked the tube off and my still runs fine has been for the last 2 months.

Split Air Pipe
 

Like you said " not true " ... If it's an S4, you do need the air pipe to open the auxiliary ports.

Or just wire open your aux. ports like rx7b13 said.

Air Pipe Pic.
 

Or you can do what I did... If you own an S4!!

I had an RB Road Race Header and had my local muffler shop to weld the air pipe and the O2 bung, kind of like the new RB model. Works perfect, the aux ports open at the same time as before betwen 3500/4000 rpm.

The tube has different purposes depending on the series of car you have.

S4 86-88, it used backpressure to open the auxillary ports, so if you removed it you will have to wire them open or use something else for them. THe racing beat presilencer for use with their header or cat replacement pipe for the S4 has a bung made to connect the pipe to which ensures continued port operation after the cat has been removed.

S5 89-91 it only serves to feed the catalytic converter fresh air to help it do it's job and if you have no cat you can simply remove it. On the S5, the airpump will open the ports for you, and excess air will just get blown out the hole that previously fed the cat.

I have an s4 so if i just cut it off of the cat and welded it to the pipe it would not work.

i got a s4 and it has a airpump, i need my cat

is there any sensors in the main cat and if so, if removed, will they kick on a check engine light... this on a S5

THis applies to the poster, as well.

All hope is not lost... You can rig your smog pump to open your aux ports, I believe this only works on S4s. Rotary resurrection has a thing on his site about it. I'm using a Precision 2-Way Metal Gang Valve that can be found at most, if not all major pet supply stores, along with a length of silicone hose.

You drill a small hole (3/32 in, I believe) into your smog pump's rear hose (the end the air is pushed from) and jam the "intake" end of the valve into it. Then you run the hose from one of the "exhaust" ends of the valve to the nipple on the LIM. You then adjust the two valves until you've got the ports opening at about 4,000 RPM. Mine cost me a whole $2.69.

I can get you some pictures, need be.

This thing works like a charm.

Also check your actuators, to see that they are not frozen, as that is no fun. If either is frozen, you'll have to remove it, and put some penetrating oil on it, and then clean off all the excess gasket material on the LIM and actuator, and then use RTV, liberally, to seal them back up. *NOTE* Be sure to NOT cover the hole that is used for air intake, or else you'll be in trouble.