First cylinder is misfiring. Changed spark plugs. Changed ignition leads and coil. Power is fine, but it misfires upon starting and when I lay on the throttle. What is my next troubleshooting area? Related Questions2005 Ford MustangWhat would make the car lose water with no leaks?2005 Ford Mustang V6My car has been running rough just in reverse and the engine light is on. What could cause this? It's fine in drive or park.2005 Ford Mustang 6clyAt what miliage is it recommended that the timing belt be changed, and how much should it cost?