An exhaust system for a vehicle having a diesel engine and a method of operation are disclosed. The exhaust system may include a diesel particulate filter, a pipe located downstream of the diesel particulate filter and an exhaust gas cooling assembly. The exhaust gas cooling assembly may have an air pump and a connecting pipe connected to the pipe and configured to direct air from the air pump into the pipe. During particulate filter regeneration, the air pump may be activated to push air into the exhaust in order to reduce the temperature of exhaust gasses exiting the vehicle.