What’s the problem?
This VW Golf 1.2 TSI is experiencing a definite misfire under load. The customer reports that the ignition coil and spark plug leads have recently been replaced. Curiously, the misfire seemed to decrease after the number four spark plug lead was swapped back to one of the original components. This raises a few questions: Are we dealing with a faulty new part, or was the original issue misdiagnosed?