After installing a boost gugage I noticed that the car only boosts 11psi at times...Like say dropping it into 3rd it will hit 11psi, then 4th/end of 3rd up to 15-16psi. Normal behavior should be full boost at like 4k rpms in 3rd.. not 11psi. Atleast that was the case on my 03.

This type of behavior was present before the installation of the boost guage, so I don't believe there is a leak anywhere having to do with the vac hose install. I've checked that hose and replaced it as well to be sure.

So basically sometimes the car boosts only 11psi, and sometimes it works normally and holds 20psi.

Could an exhaust leak cause this? The only other mod I have on my car is a catback exhaust. It didnt fit to the cat right when they installed it so they had to drill one of the holes on the catback bigger... but they said it should be fine.

I have a flashed ecu from Dynoflash, but this problem was present before I got this as well.

The first day I noticed it here in Florida was when the first cold front of the year came through, it was like 65-70 degrees...normal weather here is like 90-100degrees.

Before I got the flash I had brought the car into the dealership, they said they checked it out and couldnt find anything wrong. (but the west palm beach mitsu dealership isnt the best, by far)

Any ideas?

 

Get a second opinion. If the problem continues, try getting a MBC. Just my thoughts.

 

Also who ever installed the exhaust, maybe you should talk to them and tell them what you are noticing, see what they have to say. Maybe they will check the car out for you.

 

I have a hallman MBC, maybe i'll try putting that in.

 

11 psi is the Evo's "limp mode" setting (I believe). Either your ECU is restricting you because something is wrong, or have problems with your WGA would be my guess.

 

Wouldnt there be a CEL if that was the case?

 

check the intercooler piping for the clamps might be loose?