This might be some kind of record had a problem in February rough idle white smoke bogging down check engine light. The dealer said my EGR valve was bad they replaced it glad I still have a little of the 100,000 mi warranty left. Well yesterday simililiar problem this time bogging down with black smoke,check engine light . Took it back in yesterday. Just picked it up they replaced the EGR valve again and cleaned the carbon out of the manifold. They said carbon broke loose and clogged the valve. They couldn't tell me why they didn't clean that out last time.