Originally Posted by GeorgiaTech335coupe
From my experience, this is the differences I've seen in misfires caused by different components (don't take this as the gospel, just some tendencies I've seen):
1. If you lug your engine in 3rd and the misfires happen right away, it was usually a bad coil.
2. If you lug your engine in 3rd and the misfires happen after being in WOT for a little bit after full boost, then it was usually a bad injector (majority of the causes for my misfires).
3. If the car only misfires at really high rpm when going WOT, then it was the spark plugs. (rarely ever was the case).
Mine was the 2nd one. I realized it was for sure misfires since my spark plugs were replaced at 49k and I swapped coils but the misfire didn't follow. Here's a thread I made back when I was trying to figure it out http://www.e90post.com/forums/showthread.php?t=749067
. I have the injector in my garage and it's getting installed this weekend along with many other things.