I diagnose a #1 cylinder misfire on a 2014 GMC truck with a 5.3L engine. I swap #1 and #3 spark plugs. Still has misfire on #1 cylinder. Checked #1 ignition coil for spark output. No spark. I swap #1 and #3 ignition coils. I have spark output on #1 cylinder but not #3 cylinder indicating that misfire moved with the coil and coil is faulty.
#GMC
