A method is provided for determining exhaust mass flow through a diesel particulate filter (DPF) in an engine arrangement including an engine and an exhaust after treatment system (EATS) comprising the DPF. The method comprises determining soot loading and soot distribution in the DPF, measuring pressure drop over the DPF, measuring pressure in the DPF, measuring temperature in the DPF, and determining exhaust mass flow through the DPF as a function of the measured pressure drop, the measured pressure, the measured temperature, and the soot loading and soot distribution. An arrangement is also provided for determining exhaust mass flow through a diesel particulate filter. A method for controlling one or more engine components, and an engine, are also provided.