Rough idle

Check the EGR valve and PCV hoses to make sure none are cracked, split or detached. Best way to check all intake hoses is to spray them with a carb. cleaner like B-12 chemtrol and listen for an immediate change in idle speed and engine rev. If this happens, you have a vacuum leak to the engine which will definetly cause this symptom and you will need to replace the defective hose.