Since spark plugs are cheap, I figured I would replace the plugs, and if the misfire continued, swap a pair of coils, to see if the fault code moves to a different cylinder. While the plugs were out, I did a compression test.

Before starting, I checked www.alldata.com, to see if any precautions were necessary for the compression test. They listed none, and in fact, had a drawing of a compression gauge in the spark plug hole, with the disconnected plug wire lying nearby.

After installing the plugs, the car will not start. It does not attempt to fire, so I assume there is no spark on any of the cylinders. I reinistalled 2 of the old plugs to see if there was something about the plugs that was causing the problem, but the engine did not act like it was trying to start on two cylinders.

What are the odds that running the compression test caused all the coils to self destruct? (Or even worse, the computer)?