My 3.8 SC on a 2000 GTP has random misfiring. Seems to be when under a load or at a constant speed. Code P0352- knock sensor, code P1361 Ing. Control Circuit Low Voltage, and P1362 Ing. Bypass Circuit. Replaced Ing. Control Mod about six months ago, plugs and wires 2 weeks ago. Check resitance on coil packs, both primary and secondary, check out within specs. All vacum lines seem to be in good condition. Anyone with ideals on what the issues may be.