Code 51 will come in sometimes if the car is running. try checking the codes with the car off. 14 is ignition signal. Check teh green connector that connects the coils to the silver box(I don't know it name). If it is loose it will cause that code. Also check the primary resistances of your coils as per the TSRM. Make sure you have a good digital multimeter.
I had a code 14 that ended up being the small wiring harness that goes from the coil pack to the main engine harness. It drove me nuts for months. Make sure you check ALL connections that are around your coil packs and ignitor. Good luck