A device and method for heating exhaust gas from the combustion of fossil fuel upstream of an emissions control device, especially a diesel particulate filter. A conduit receives an exhaust gas flow, and is in fluid communication with the emissions control device for supplying exhaust gas thereto. A flow straightener is disposed in the conduit, and a portion of the exhaust gas flows through the flow straightener. An igniter is disposed in the conduit between the flow straightener and the emissions control device for igniting fuel supplied thereto to produce a flame to heat the exhaust gas flow.