When using a boost at 0.9 my car suddenly stops boosting at 6500 revs (boost goes to vacuum, i see it on my stock boost gauge). It looks like it's a knock sensor cut, but i'm not sure. If using stock boost - everything is ok. I've tried to make fuel mixture richer and leaner, but it didn't help. When i drive with a hood little opened - looks like everything is ok. I thought it is bad oil (had same problem before and oil change fixed it), but after changing this stuff happens again. Looks like the incoming air is too hot and causing the detonation.. can this be a problem?