Hi. I hope someone can help me out , i have a06 Eddie Bauer 4.0 that has a # 1 cylinder missfire under load. the harder the load the more it misses. I have replaced the plugs with E3 plugs the wires with standard wires and the coil pack with motorcraft coilpack but still have the miss . Is this a common issue with the 4.0 ? Any help would be greatly appreciated.