3.9L V6 van was running OK, then drove 26 miles in heavy rain. got a P301 code for misfiring cyl 1. Went ahead and replaced all 6 plugs and the plug wires and it ran smooth as silk for 2 days. Ran OK at startup but 10 minutes started chugging and hesitating, now have P0316, P0300, P0301 and P0305. Sounds like it could be an ignition coil pack going bad? What else could it be>
Thanks!

 

Could be the coil pack since it's a 2004 and the coil is a wear item that breaks down over time due to excessive temerapure changes. Did you use dielectrical grease on both ends of the wires inside the boots? The P0316 code is for the Crankshaft Position (CKP) sensor. This could also be your problem. However, the coil is easier to replace and may need replacing anyways. My coil was causing hic-ups while driving at highway speeds that felt like tranny jolts. Have had no issues sionce replacing my coil 40K miles ago.