Iam a new member I got a misfire with cylinder2 on a 2007 Mazda Cx7 with 140000 km .changed spark plugs and coils around made no difference and code reader still says misfire cylinder 2 (p0302) and dealer recons it's a coil maybe different cylinder not that one but plug isn't firing properly black and the rest are clean ish even with coils changed around thanks in advance