dad's van misfiring
 

dad owns a 3500 Express van 2002 3/4 ton and is missfiring went to auto zone to get the SES light diagnosed. Changed wires and plugs but still doing it but less. Anyother things i could do???

So what did AutoZone tell you the DTC (SES code) was? :)

What is the engine size - 4.3, 5.0, 5.7, 6.5, 8.1?

What symptoms/problems have you noticed? Noises, fluid consumption?

coil pack,,,,, is it doing it just under load or also at idle??