I have an '04 GT that I bought 2 years ago from the dealer, that turns out has a bunch of mods. There is a pulley system installed and for about a year now and after spending about 2K on trying to fix the problem, I was hoping to see if anyone has had this problem before. What happens is at any random point while driving it loses significant engine power and I can feel the whole engine bog for a good 30 seconds all while the check engine
light blinks. The codes that are being spewed out are misfire codes for all cylinders, but after changing all the plugs, coils, boots, checking compression on all cylinders, swapping out the whole computer for a new one, I have the same issue... Has anyone else gone through this!? Or can anyone tell me if I'm completely missing what it could be? I don't want to sell this car, and I don't want to keep throwing money at mechanics to not fix the problem. Please HELP!!