[Serf27]

I’ll try to explain this as best as possible.
Car is 07 335i with jb4, bms intakes and straight piped from turbos all the way back.
I also did that cheap bov mod where you use a rubber plug where the recirculation tubes go for more pshhh.

When taking off from a stop, in first gear if I go WOT, I hear the boost being released, (pshh noise.)
I usually only hear that noise when I let off the accelerator after building boost.

Now at WOT I’m first, I hear it sometimes one time and other times I hear it twice followed by a backfire.

Any idea what’s causing this? Could it be the diverter valves?
I may also have a boost leak according to jb4(low boost mode) that dme code pops up only sometimes.