Have fun pull all coil packs in that van.
Pull and inspect for crack body if not then pull boot and spring off then add dielectric grease on both side of spring then put back in there.
And keep driving van with that issue will ruin your cat convertor fast. I drove mine for like 200 miles later to find 2 spark plugs hole were full of water on #5 #7 cylinders. After that mileage never went up until I remove cat convertor it was plugged fast.