I tried searching... went through 6 pages and gave up.

So my question is, would i need a tune after a cat back? This would be my ONLY mod.

 

It is not necessary but even a stock evo can use a tune and see decent gains.

 

Yeah, but i figured, i wait another month or so to get the tune, so i can buy a fuel pump, intake, and MBC, and combined with my exhaust, then get a tune.

 

You will be fine, I would make sure you get the tune obviously after the above parts are installed!

 

How about a full turbo back exhaust? 3"... Previous owners mod...

 

no you'll be fine

you really wanna get a tune once you put in a fuel pump, boost controler, cams ect.

 

Here's a good example of tune + tbe on my car 5 years ago, although not ER-tuned at the time. Baseline (red) pull is OEM tune with turbo-back exhaust and a high flow cat. After (blue) pull is with tune and more boost.

 

That's sweet to see them compared like that. I'm used to just seeing the new dyno sheet(s).

 

^ before and afters pretty much take what kind of dyno it is out of the picture. This was same day, same car, same mods, same dyno. Just shows what a tune and more boost can do.

 

Save your money and wait until you have some more mods.