Hey all, I made a post similar to this a few months ago, and seem to be having the same problem again. I would, most of the time, get full boost, 12-14 psi depending on weather conditions.
A few months ago, it would not get past maybe 9 or so psi, making a strange whooshing sound, almost like the turbo was just much louder. Now again, after ordering a ZZP PCM, the problem is back. It is fine with the stock ecu, but with theirs, i can never boost past 10 psi or so, depending on the gear i'm currently in. I talked with ZZP via email many times, and they were very helpful, even sending me a new ecu to see if it was the ecu causing the issue. The problem is obviously on my end.
-There is no CEL at all, no boost leaks at all, I checked the bpv for tears, and anything else I could fine on here or any other site. Any insight would be appreciate as im just running out of ideas and things to check now.

 

Intercooler cracks in end tank maybe

 

How did you test for boost leaks?

More info is helpful, miles, mods besides zzp ecu, plugs, etc

 

I went over both Intercooler pipes well, checked the entire intercooler for cracks.
The car has 73k miles, only other mods are mpx catback and AEM intake right now. I haven't done a proper boost leak test in many months though, just an inspection of everything quite well.

 

Do a proper boost leak test, it can look/feel fine but leak like no other