I took my VW Golf MK5 2005 (130,000 miles) to have a full service the other week which included changing all 4 spark plugs. Whilst driving home the engine management light came on and I lost some power in the car.
I took my OBD reader which showed there was a cylinder 4 misfire. I took it back to the garage the next day and they tested and told me it was the ignition coil for that cylinder. They informed me that the coils can be quite delicate and don't always liked being moved. To be fair to them they only charged for the new coil.
3 days later after moderate driving the same situation occurred and I lost approximately 25% power again. The OBD reader showed a cylinder 3 misfire this time.
My question is will this most likely be the ignition coil again for the 3rd cylinder and is this the fault of the garage who did the service? If it is the coil then I am tempted to just change it myself.