Help...Sputtering/backfiring/stalling problem 03 Heritage Classic

Aloha all,

Question that hopefully someone can shed some light upon. I have an 03
Heritage Classic, V/H pipes, combined with new air intake, it is EFI... no
problems for several years.. just under 20k miles in Hawaii... Ridden
almost everyday when not at sea. A few months ago it started to backfire,
and seems to be sluggish upon takeoff and occassionally while riding. I

Happened to Harlista last year on the way to
SNIFF.......hole was about 1/2 way down the pickup tube, his
Ultra ran fine as long as he kept it at least 1/2 full.

Under half full it started sputtering, choking, etc.

have carried it in twice and the Harley dealership here keeps telling me it
is the new gas.... I would by that except I also have an 02 Fatboy, also
EFI and have the same mods on both... It has no problems... This happens
whether the bike is hot or cold, various speeds, and it is not all the time.
I have put in the fuel inject cleaners, the higher octane booster stuff, and
always put in 91 plus for octane rated gas....

Bike is still under warranty and we both love to ride, I am just not as
comfortable riding on a bike that does not seem to be performing at 100
percent capability. I did not go with a power commander, but would if that
could possibly correct the problem.

We have been riding for years and do not relish the idea of getting rid of
the bike... we love them both... Any assistance would be greatly
appreciated... The bike so far has spent almost two weeks in the shop with
them unable to identify the problem or give any advice on how to resolve. I
got new plugs and everything I could think of to resolve the issue with no
luck.
Thanks, ride safe, and have a great day,
Sincerely,
Navydavy in paradise