My wife was driving down the highway in her 960 and it started chugging and wanting to stall. after going through the engine i realized that 3 of the coils are not working. i swapped one of the other coils with one that is is not working and it still did not work in that position. I read through the forum and it seemed that everything pointed to one of the two Ignition control units being the culprit so I followed the wire coloring and replaced the one I believe to be controlling these three coils. still not working. The engine will idle on the other three cylinders very rough, and i can unplug the three unworking coils with no change. the position of the coils that are not functioning are from the engine firewall towards the front of the car: #1, #3, #4. Any suggestions here?