hello, my camry is having an error code of P0401 inwhich its the EGR and when i drive it for awhile, i guess when it gets warmed up, from stop to go, smokes shoots out and then it doesnt. now it doesnt smoke all the time but alot of the time. can the EGR if replaced stop the smoking or is their anything else wrong with it. also i havent changed my fuel filter. can that be the cause also. thank you