Air pump!
 

What is the purpose of a airpump? And if there is none, would it cause my engine to misfire at all? Help would be great! I keep getting bs answers on google and such so figured id try here..

On all FCs, it is for smog purposes. If you have a catalytic converter, you should not remove it. The cat could fail and clog up.

On S5 NAs, the airpump operates the 6PI (aux. ports) and VDI (variable dynamic intake) system.

The air pump pumps air into your exhaust system. What it does is lower the parts per million of exhaust fumes coming out of the tail pipe. It's a cheaters way to get around emissions rules by making the car seem like it's polluting less.

No, that is not what it does. Oxygen in combination with the catalyst in catalytic converters allows both the oxidation of carbon monoxide to carbon dioxide, and the oxidation of hydrocarbons to water and carbon dioxide. If it were a "cheater method" the EPA would throw a hissy fit.

I'm guessing your car is misfiring? Could you explain the symptoms?

So, if I were to remove the Cat and the Air pump would I have to also convert to an electric fan on my S4? Doesn't the air pump pulley help drive the water pump, more so than the alternator belt? I've been trying to figure out how to get rid of this thing since emissions aren't really a concern in Ohio.

If you don't know the right answer to a question it's better to just not say anything at all than to say something that is completely false.

You need to get a better understand on how emission system works.

You touched on the one main thing you have to be concerned with when removing the air pump, and that's the water pump pulley slipping. The common fix is a double alternator pulley to get more contact on the water pump pulley. Some use what's called a "yoohoo belt" that goes from the main pulley to the water pump pulley alone, but it has to be somewhat elastic or it is impossible to slip over the pulleys.

Here's an example of a double alternator pulley on my engine. I have no air pump. I do have an electric fan, but you can still use the stock clutch fan.

https://www.rx7club.com/picture.php?...ictureid=21608

Awesome, this is exactly what I was expecting to have to do. I've been having trouble confirming this though. Thank you!