Boost cut out for a second then come in again

[Russp4]

Is the boost an electric problem?it cuts out n back in

[savage bulldogs]

Subaru's are renowned for cutting boost when low on fuel and exiting a corner,  due to the fuel sloshing over to the opposite side of the fuel pick up .

Or if its doing it with over half a tank or in a straight line , then do you have any unmapped mods (especially airflow mods) ?