Low Boost/ No Vacuum Leaks / Logs Inside

Alright so here is my story folks, a few month ago I noticed that the car got slower than it used to be. So I a decided to pull a few logs and check things out. BTW I am at Stg 2 Infamous 1 94 octane tuned, K&N and Downpipe.

 

First things first, I checked all tubes/connection, under the IC. Everything seemed fine, no leaks that I could find. Next thing I did is I went to a very reputable Subaru garage and they did a smoke test and also didn't find any leaks. They have advised to try and change the plugs and see if this helps. So I went ahead and got my plugs swapped, but still it seems that I am not hitting my normal levels. There is another issue which I haven't taken care of yet, which is the leaking intake manifold gaskets, it causes the car to be a bit rough in very cold temps until it reaches normal operating temperatures. I was told, it will not cause the boost to decrease.

 

Here are two logs, one dating back to Sept 10 where I was hitting my full boost and the other log taken yesterday, also a LV taken yesterday attached.

 

Any ideas what might be causing this?

 

Thanks!

SEpt 2010 Log.csv

Feb 2011 Log.csv

Looks like a leak to me...did you check the TMIC itself? If you running the stocker it is known to start coming apart at stage 2 levels.

I had smoke test with a professional machine done, and there was no sign of leaks. Now I didn't check my exhaust for leaks, but I don't believe it will cause such a condition, unless it is severe, and in that case I could probably hear it.

If there aren't any leaks, its probably a wastegate issue. There are threads around where people have had problems with it sticking open for various reasons.

If there aren't any leaks, its probably a wastegate issue. There are threads around where people have had problems with it sticking open for various reasons.

 

I think you might have a point there, checking my attached logs once again, it appears that in my Februarys logs I am having the wastegate letting off pressure even though I haven't hit boost yet.

 

 

Comparing to my Sept logs, the wastegate actuates only once the boost is about to be hit and also the number values seem to be higher.

 

 

Would that suggest an issue with the wastegate, how do I go about checking it and where do I find it?

I have no idea how to check or fix wastegate issues. I just remember seeing stuff while doing research about my boost leak. Mine turned out to be a cracked intercooler endtank, but others had reported wastegate issues. You may want to try the turbo technical forum or talk to the shop you worked with before.

valerka did you ever find out your issue? I'm going through the same thing and sometimes it's low and sometimes it's not. I found a leak at my bpv and IC to turbo and fixed that. It took a boost leak test by pressurizing the system and spraying soap water on everything after finding nothing on a smoke test. I also found a leak on my down pipe I fixed. Still I am randomly getting low boost from time to time.

 

I was also tuned by infamous on a stage 2 93 octane tune.