I recently purchased an 04 wrx through an auction. The car is completely stock and has 60,000 miles. The engine is missfiring very badly. At idle the engine shakes side to side on the mount, wont rev past 4500, and has very little power. The turbo sounds like its spooling just fine, but i dont have a boost guage so i dont really know. After running a diagnostic i found that all 4 cylinders are missfiring. The mechanic that ran the diagnostic told me that i need to replace all the coils and spark plugs.
I ask this, does it seem likely that all the coils would be bad? What are the chances that they would all of them would fail at the same time? Has anyone ever had an issue like tis before? I have heard of one or two cylinder misfires but all 4?
Also, after inspecting the engine i noticed there is a thin metal braided wire that is routed underneath the intake and ends somewhere near the turbo. It is unplugged and i cant seem to figure out where it is supposed to be plugged into. Any ideas?
I would really appreciate any tips. I dont want to spend $400 on parts i really dont need. Thanks