I have two leaks that I found when I did my boost leak test. One is at the BISS and the is lower. I was told to put 1/4" o-ring at the BISS to fix that leak, but what about the bottom one. Just for reference this is a Turbo'd 2003 Mitsubishi Eclipse. Its our TB but they're almost identical. I have an evo one to put on but I just need the pigtail for the TPS.

 

i had to replace the o-ring on that lower one also. just go to a auto parts store/ hardware store and get a matching o-ring or prob just get a o-ring kit like i did. mine was a little too big but i just popped it on and screwed it down (used a little rtv just on the cap). works fine with no leaks. o id check ur throttle body seals. i went thro all of this too and it just kept being another leak after another. save urself the time and go thro the whole thing.

 

I'd get a hold of Mil.Spec for this. They seem to know the TB pretty well.

https://www.evolutionm.net/forums/ev...available.html

 

I wouldn't bother replacing the TB seals in all honesty, I think it's only apparent when actually looking for it.....if you do a boost leak test, and put a little pressure on the TB spring, you can make the leak stop. I fixed a couple of other leaks on mine, the TB seals were also leaking, which I didn't bother to fix, the difference on the road is so negligible as to not make the effort worthwhile.

 

not arguing but it only takes a few minutes to get the TB out of the car, also a boost leak is a LEAK! shouldnt be there and that little bit can be hp. after replacing mine and having my system 100% again i couldnt believe how great the throttle response and power i was loosing

 

Oh yeah, if you can be bothered to do it, fair enough, all I meant was that I think when on full throttle the leak isn't really there, I think it's more apparent when doing the test than when actually driving the car.