08 STi not boosting.
Starting yesterday, I am not boosting over 10 PSI. The car is stage 2 with a catted Cobb DP, Blitz CBE, and an AP with an OTS map from Cobb. The car was boosting 17-18 PSI I believe, but now it's usually boosting about 8 PSI and I was able to get it to 10 PSI in fourth going up a canyon freeway. AFR is remaining at around 11 under WOT conditions, the car shows no ignition advance/retard. I parked it outside overnight, which I don't normally do, but I've been working on my dad's car in my garage so I left my car in the cold. I've warmed up the car and drove it for a couple hours total yesterday as I took it snowboarding. WG Duty is not doing anything at all. I don't know that it would do anything below target boost anyway. I can't find any vacuum leaks, and I also have no exhaust leaks either. It also does some weird surging (under minimal boost) while I leave the throttle in the same position. It's worst right when the turbo should be spooling up around 3K-3.5K. The surging feels most like a spark-based lag, but the car only has 18K on it, so I can't imagine there'd be an ignition problem. . . I could be wrong? This was rather sudden, and I only noticed it yesterday morning, but I had done a bit of freeway driving the night before so I hadn't really pressed the throttle, but it definitely started within the last 48 hours.
I have an appointment on Monday at 7 AM at the dealership for them to take a look at it, but if it's something I can do, I prefer to fix stuff myself.