Motorcycle Repair: Problem with, heritage softail classic, 2003 heritage softail

Question
I have a 2003 Heritage Softail Classic w/EFI and around 9400 miles on it. I've had all the services done at HD Dealer but this year I noticed a problem with the bike after riding for a half an hour or so.  


What could cause my motorcycle to misfire only when going up slight inclines or hills. It seems like the motor backfires and looses speed. I have to downshift to a lower gear sometimes all the way down to 3rd. to recover for loss of speed. It has even stalled several times with the service engine light comes on. I have replaced the spark plugs, wires and even replaced the gas thinking condensation in the tank. All to no avail.  

Answer
The only advice I can give you is to take the bike to your dealer and have them run a diagnostic on it. There are so mamy things that can cause this problem with a EFI bike that you would be waisting money changing parts that might not be broken.
Good luck and happy riding
Mike