An engine brake system and a method for controlling the exhaust gas pressure of an exhaust system for a vehicle provided with an engine are provided. The system includes a main exhaust gas conduit connected to the turbine of a turbo arrangement and an Exhaust Pressure Governor (EPG) which is used to create a backpressure in the exhaust system so as to function as an engine brake. The turbo arrangement includes a Variable Geometry Turbine (VGT). The Exhaust Pressure Governor is located in a bypass conduit which is connected to the main exhaust conduit upstream the connection to the turbine of the turbo arrangement and the main exhaust conduit includes a valve arrangement downstream the bypass conduit connection for closing the main exhaust conduit. According to the method for controlling the system, the flow passage through the main conduit is open and the flow through the bypass conduit is closed in response to an output control indicating that no engine braking is desired. In case there is an output control indicating that engine braking is desired, the flow passage through the main conduit is closed and the flow through the bypass conduit is open whereby the EPG is controlled to provide a desired backpressure according to the control signals from the control system.