Had my 97 A4 QT (28k) towed to dealer due to misfire, burning smell, engine light flashing. Diagnosis was replacing wires to the #3 coil pack.

Anyone have the translation on what they fixed
and what the coil pack does? The engine sounds
quieter and I have more pickup.

A coil pack is part of the distributor-less ignition system. It is computer controled and supplies power via wires to your spark plugs. It appears that a faulty wire from the coil pack to the spark plug was replaced. A bad wire would definately cause a miss-fire, and an overall poorly running car.