The P0401 is a fairly straight forward code pointing to a fault in the EGR System. On this vehicle, the EGR Valve is all inclusive with the solenoid, so the EGR Valve must be replaced as a unit (the new EGR will come with a new solenoid). Check the electrical harness for any broken or loose wires. Check the rubber lines for any holes or disconnections. I fthe visual inspection checks ok, replacing the EGR Assembly should solve the problem. The EGR Assembly sells for around $149 and the labor time guide calls for just under an hour to complete the job. LAbor rates vary from shop to shop, so what you pay for labor will effect the botXXXXX XXXXXne.