I did read post 2. The misfires have occurred in all four cylinders, not following an ignition coil.

I took it to the dealership today hoping they could find the problem & fix it fast.

The dealership swapped my ignition coils around and the problem today stayed in cylinder 4, also not following a coil. They also tried a new mass air sensor but that didn't fix it, so they reinstalled my original one. They detected a rattling sound in part of the pipe that goes to the muffler, disconnected it, but that made no difference. They buttoned everything back up, no cause found. I'll be able to work on it at home over the holidays.

I see no reason why both of my coils didn't age at the same rate. Thus, if a coil is bad, perhaps they are both bad.

I'm tempted to buy two new coils online for $100 and just replace them.

I'm probably not competent enough to handle the crank sensor work you describe.

Thanks for the help