Is everyone sure it's coils? Does it sound more like a wrx or a lawn mower? dude it may be your turbo gasket from your manifold side! 500 bucks is a bit much to spend if it's not the right thing thats wrong! thats all! and the jjrs a good but really u pay for what u get splitfire just has that reputation and plus the japaneese use them in the 1000hp supercars! so it's saying something