So My brothers S3 with Beach buggy hybrid is having some problems. We had it mapped by Badger5 but only got to 280bhp due to the wrong spring in the actuator (too weak) We drove it home ok. But a day or two afterwards it developed a nasty hesitation at 3000rpm. So my brother replaced a Coil and it dissapeared.....until the next day. Where the stutter was backl with vengence! It now happens all over the rev range when a decent amount of throttle is applied. He changed to 2 oldest coils yesterday and the problem disappeared. For a few hours of mixed driving, it was fine. But its back now. He has a brand new Fuel pump to go in. But we are unsure of the: What is causing this? Why when we changed the coil packs it stopped doing it then returned? Any ideas??