I recently did a turbo upgrade on my Evo IX and it bounced around to a few shops. When all was said and done, I was pretty satisfied.

So I started doing some normal maintenance today (oil, plugs, filter) and came up with a huge shock. Someone put Evo 8 plugs back in my 9 which are about 1/2 inch or so shorter.

So I'm not sure how long I've had Evo 8 plugs in my 9. Maybe this would explain the random misfire issues I've been having.

Anyone think that putting the correct plugs back in will have a significant effect on my tune since im positive it was tuned on the shorter plugs?