Where should i start with this code?

hello i have a 1999 nissan maxima with the check engine light on displaying code P1320- Ignition signal primary fault... i was having some hesitation problems but found out cylinder 5's coil went out and i replaced it and corrected the hesitation problem and misfire problem, the car is running great, power and acceleration are back and it also is getting better gas milage and idling better but still has code P1320 if i clear it is just comes back on... i checked the cam position sensor is it good and i checked the harness and checked voltage at all coil connectors and they are all good i checked all the coils themselves and the tps, i would think that with that code i would have a miss or a hard start but it starts right up and drives nice.. im not trying to complain about a good running car but the light is very annoying and i want to make sure something else is not broke or is about to break. thank you...