So I was changing out vac lines, when I noticed a restrictor pill on one end of the T fitting 'line to the gauge'. Is this right? I haven't been able to source any information. Also, I have an AEM mechanical boost gauge I wanted to install, would I use this T fitting with the restrictor pill?

 

Ive seen them come with a boost guage ive bought in the past. Dont think you need it. My car dont have one. None of the evos ive ever worked on have had one.

 

I posted about this years ago, and no one ever heard of it. I bought the car new in 2004, and no one had ever touched the car before I found the "restrictor pill" in the same location as you did. You should get rid of it. I found it because my oem boost gauge was sticking on acceleration, and then releasing after a few seconds. No problems after I eliminated the restriction. I later changed to an AEM digital boost gauge, and left the restrictor out then, too. You're the only other person I've ever heard of who found the little bugger. No mention in the shop manual, and Mitsubishi couldn't find any referrence about it.

 

mine has one as well, I've been wondering about that.