The boost modulator with its 3 hoses and an electrical connector is located just above the pipe going from the turbo to the I/C. It often fails in the position of never passing turbo pressure to the wastegate actuator which results in too much boost. Whilst 2700 is a little higher than normal, the surging is a sign of fuel being cut. Connect a hose from the turbo to I/C pipe pressure outlet directly to the wastegate actuator to revert to base boost of 1 bar as a temporary fix. The modulators are not expensive.
Edit: Whilst disconnecting the MAF will prevent the ecm from operating the boost modulator to use more than base boost, it wont prevent overboosting caused by a failed boost modulator.
