My truck has been eating fuel pretty bad then the light came on for water in the fuel had them changed now when i come to a stop sign it wont go it just chugs and barely moves and blows mager amounts of smoke eventuly it runs ok again i brought the truck to the dealer and they are saying its the egr valve a friend said it cant be that i never got the truck back yet they said there waiting for the part can any body tell me if they had this happen and what it is.I have 15000 on truck Thanks Dale