Question about air pump
 

I removed airpump to get more power to the engine. Should i re install or get rid of oil metor and rats nest off?

You don't gain any power by removing the air pump. Depending on what series you have, you actually LOSE power

Removing the air pump is a marginal HP gain at best. If you have an S5 NA, you will lose power as the aux ports are not opening.

Just removing the air pump is going to cause other issues as well. With no air pump, the cats will die a quick death. The entire emission system is basically disabled as well.

Definitely do NOT remove the metering oil system unless you have a very specific reason to do so.

As for the rats nest removal, that's also a no. There is no power gain and then you'll have to deal with the engine not running very well unless a lot of time is spent to compensate.

your profile says you have an 89 ..so you can't take the OMP off unless you have a way to trick the ECU.
Without that the engine goes into limp mode.Say BYE to having a car that runs right and drives nice..
Look up RTEK ECU.

You also will lose HP removing the air pump because it works the VDI and 5th/6th ports.