This error code P1408 is a failure of the EGR valve circuit (gas recirculation). If you get this error code, try removing and cleaning the egr valve spun bar but at the same time, clean the opening of the EGR port where the EGR valve is installed.
If possible, clean the aisle that drops from the port to the throttle body. Using an air blower, the ducts can be blown and soaked with carbohydrate cleaning sprays to remove build up carbon which limits the exhaust gases.
In some engine models, it is necessary to remove the upper intake manifold to access this port opening.