Just a small reminder for those using Resistor plugs on 104 engines---
These engines already have resistors at each plug inside of the plug connectors . And most importantly, these are not conventional ignition systems , but rather Waste Spark systems .. meaning , each coil fires a series circuit through 2 plugs in order to complete the spark circuit. That is why 3 coils for an IL6 engine.
The wasted spark does not require a high coil draw cuz it is firing on an exhaust stroke [ thus , wasted spark] and is not under the demands of a compression stroke firing. But the system is still taxed beyond a regular ign. as it still has to jump two gaps to complete a circuit.
So , when adding R plugs on top of what is already there , you are doubling the resistance and further taxing both the coils and , more importantly, the switching driver circuits in the ECU. As of late , these ECU have been popping the heat sinks right off the switching transistors due to eccessive current draws . Adding the unneeded extra resistance of R plugs to this series circuit only shortens the longevity of the electronics involved.and they are $$$$$$$$$$$$$$$$

One will note that all 104 engine take the Bosch F8DC4 , non resistor , copper core plug and they run fine with them.
If one finds no misfire problems on 104 ign. with R plats , it is an unusual case and they will have future problems with the drivers and coils way before due .