I have an 04 Evo 8 rs. I just recently did a boost leak test and fixed two major leaks one being the idle bleed flapper. And have noticed I am still leaking slight from my Omni 4 bar map sensor. I took it out and replaced the o ring but it is still leaking during boost test. Any suggestions?

 

If at all possible, ditch the OMNI for something else, they suck. If not....replace it with another omni.

 

Put a very small amount of sensor safe rtv around the o ring, have been doing this for years with no issues. idk why but i was in the same boat even after replacing the oring.

Otherwise people get a thicker ring.
https://www.evolutionm.net/forums/ev...ed-o-ring.html

 

I was going to mention fitting a slightly thicker O-Ring

I have a nice little case with probably 50 different sizes. Worth having in the garage