Corrosion may develop at the connection between the ignition coil tower and spark plug wire resulting in an engine misfire. The Ignition coil and spark plug wire should both be replaced to correct this condition.Google+
Car Problem Reports
Pontiac Grand Prix Corrosion At Ignition Coil Towers
Pontiac Grand Prix Problem
Engines Affected: 3.1L V6, 3.4L V6
Average Mileage: 113,750 mi (112,500 mi - 115,000 mi)
Visitor, 2003 Pontiac Grand Prix, 3.1L V6, 112,500 mi
Vehicle would misfire between 1500 and2000 rpm with the gas pedal position held at a cruising speed. Two ignition coils each had one terminal with excessive corrosion. Replaced both coils and the plug wire set.