replaced all the coil packs with new ones
havent checked plug wires
codes: po302 po304 po307 and po308
So I went down this road with my truck (2V 4.6) thought I had a coil that went bad and changed them all only to discover that I had a coolant leak that was causing the issue. The plastic intakes are prone to blowing the gasket and the coolant gets into the plug hole and shorts out the spark. Check the coil boots for moisture when cool. Mine also had an internal leak that put coolant into the intake furthering the misfire but the external was the root of the misfire.Looking for help on my misfire issue i've been having on my 2012 GTCS. I am getting misfires on cylinders 2,4,7 and 8. I have checked spark plugs coil packs and fuel injectors already. Have no idea what is causing it. Any help is appreciated.