my jetta had code 1248 come on. when driving if you let of the gas for a second or two then step on it again it just seems like it wants to die and even seems like its downshifting as you slow down and starts blowing ALOT of smoke and one time it slowed down so much i had to pull off the road and come to a complete stop then it ran fine but still blew out the extra smoke for a while. other than when this happens it runs great.