Spark, plug wire resistance

i will try to find it. it is under jeep as it was originally dealing with grand cherokee"s but was later changed to include trucks. may be under drivability section. my buddy, that was a teacher at the st. louis ,mo training center, district mgr and now a teacher at siue carbondale,il, said you will not find a code in system, even when scanner is hooked up while driving and it dies.