Have had the car over a year now, done 5000 miles faultless driving until the other day. Driving back home, it suddenly decided to miss and run on 3 cylinders, it then decided to alternate between 3 and 4 for the rest of the journey and now is only running on 3. I went obvious and changed the plugs, no difference. Then taking off a coil pack at a time, from left to right, the engine would struggle (as it was only running on 2) until I took the 4th coil pack off and no difference to the lumpy, miss firing engine. Bought a new coil pack, tried it and still the same :/ Tested the new coil pack with the wiring for 3 and it's fine. Stumped now, all wiring and connectors look good, why isn't coil pack 4 firing? Any help would be much appreciated.