What is the procedure for checking the individual coil over plug coils using a volt meter. Changing plugs tomorrow and want to test coils while removed.
A good way to test (as long as you have a dead misfire) is by either unplugging the coil or injector while you have someone brake torqueing the vehicle (makes misfire more noticeable) and when a certain cylinder isnt affected obviously that would be the one misfiring.
If there isnt a misfire then there is no reason to check. Another thing I have found is condensation in the plug boot. Pull the boot off when the coil is out ( be careful not to damage the spring) and see if there is moisture inside on the spring/boot. I have seen that cause a misfire before, and you can get replacement boots.
I have seen cops go 250k. If they aren;t maintained and see alot of internal moisture that can cuase the cracking issue. If it needs plugs and coils. Deffer to a proffessional family with the engine. It is easy to have a popomatic that will throw spark plugs outta the heads for fun.