So recently my stock bcs stopped working and I replaced it with a hallman type mbc. I have a tuner that's been etunning my car and has been great to work with me. So I installed the mbc and slowly started to adjust the boost level to creep up to the target level which was around 17psi. After passing 13-14 psi I start to get fuel cut and the car lunges. The only time I've ever had the same issue is when I was overboosting due to a vac leak some time ago. Tried a new tune setup and still having issues. Wondering if I should continue working with the tuner or if I should be looking at hardware that could be the cause. I've read that the stock bpv sometimes has this issue but I switched mine out with a friends STi a while back when he was trading up so that shouldn't be the issue. No apparent air leaks and the only mod is k&n typhoon intake. Just hoping for some feedback before I continue to bug my tuner.