It is common to have an intermittant coil problem , and usually that would be on the secondary windings side [ but not always]. The ECU actually triggers the primary and spark occures when a pre-determined current is reached, [ spark circuit Ramp] so one could also have a bad trigger threshold in the ECU. That is why I had you try another location for the coil. If the code follows the coil , you can assusme the coil /connector is bad ..if it did not , it would point to that trigger Transistor circuit in the ECU..[ which does happen] or a bad plug/injector/etc at that same cylinder....this swapping stuff around to make a diagnosis is commonplace if one does not have the proper diagnostic equipment and even a good shop will use these quicky test...
The oddity of the Waste Spark system this chassis uses is that the 2 plugs are wired in Series with one coil, meaning the flow goes from coil to electrode of first plug , fires to ground and then on the second plug it goes from ground to electrode for fire and back to the single coils secondary winding to complete the circuit...so, that is quite a path and a couple of plug gaps to overcome..Of course , the second plug offers no load demand [ b/c it has no compression/fuel mix], so it has an easy jump, but even still, there is that contention... knowing this , one can see why the coil to plug connectors are so important, as they can effect both plugs firing as they are always in the circuit, regardless of which cylinder is under compression load................. [ any weak link/connection in a Series circuit shuts down the complete circuit].
I also believe that this plug firing arrangement is the reason these models do not take a likeing to Plats with their ultra-thin electrodes..[ but that is just my guess and may not be a viable reason, even tho its seems to make sense]
The later coil over plug versions use coils on each plug.
I used to be able to just see the electrons path until I got a lethal dose of that Kriptonite stuff...now I have to use a DSO....The Scope allows you to see the signals and wave patterns just as the ECU sees and reads them..so that narrows it right down simple.
Give me a schematic, a jumper , and a test lamp and I am all set to go at it
on the older cars , but these High Techers need equipment to really get it down w/o some guessing, as you could see on that Video..............

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A Dalton