saxo vtr misfire at low speed

  1. Newbie Joined: Jan 2012 Posts: 10 Saxo VTR 1.6i. Lowered 40, drilled & grooved discs
    #1
    My vtr has developed a slight misfire when I'm at about 40. & trying to accelerate but once I blast it passed 70, its OK for a while. Could it just be plug breaking down? Thanks