My '18 Road Glide Ultra (out of warranty) intermittently stalls, with P2300 & P2303 ECM codes. The 1st time, I replaced the coil (even though it tested ok), cleaned all grounds, checked continuity of ALL power supply & ground wiring to/from all 3 ECM connectors, & checked plug wires for chafing/wear/burns (no issues found, but replaced with SE 10 mm wires anyway plus new plugs). Started right up, ran great about 5 miles, stalled again, same codes, wouldn't fire. Went to get a trailer & some help to load it, and decided to try it again before loading on the trailer. Started right up! Rode it onto the trailer, rode it into my garage, started it several times over next 24 hours and let it idle, no issues. Decided to road test it the next day, only went 1/2 mile, stalled again, hasn't started since. Replaced crankshaft position sensor, no dice. Any similar issues out there?

 

Bad coil(s) or related wiring.

 

As I said in my post, the coil is new, plug wires are new ( installed carefully using dielectric grease on all connections), and all wiring has been checked.

 

Then that leaves wiring to the coils, bad battery/connections, or low voltage. Especially since idle is relatively good but as rpm rises and vibration and more power needed to fire coils.