a 2002 Road King has no O2 sensors.
the MAP sensor has little to do with the air/fuel mixture and is not likely the cause.
the most common causes of your issue are:
- changes to the air cleaner and/or exhaust without tuning the fuel map.
- problems with the engine temperature sensor.
- problems with your battery and/or charging system. (if I had a nickle for every time someone with a bad battery told me the "battery is good", I'd be a very rich man)
in cases like yours, I prefer to check the battery/charging system first. this is the easiest check to perform and doesn't usually cost anything.
if you would like my help in narrowing down your problem, measure the battery terminal voltage under the following conditions:
- ignition OFF.
- ignition ON.
- with the start button depressed.
- with the engine at about 2,000 rpm (fast idle).
let me know if you need more help.