There will be a coil over the #1 cylinder which is the front most cylinders in 1 of the 2 cylinder banks and the wire from it will go to the #4 cylinder. Be sure to check the wires and plugs, because a misfire on even 1 plug will set a misfire in 2 cylinders, because this is a waste spark system. When I fix a problem like this, I always replace the plugs, wires and the coil in question with factory parts. After Market parts for these problems are risky.
I tried to follow your guidance and I'm a bit confused. There are three coils across the front of the engine. Each coil has one spark plug type wire coming out of it and going to the back of the engine where I can't see them anymore.
Is it possible to telll which of the three coils feed which cylinders (from L to R) when standing at the front of the car?