Motorcycle Repair: backfire/popping sound during deceleration, straight pipes, eagle air

Question
QUESTION: I have 06 Road King Custom, EFI, Screaming Eagle air cleaner, and Samson Fishtail slip on pipes, i have re-map system as suggested by the reps @ Power Commander, but i notice when i am decelerating i hear popping sound, usually at speeds between 55-65MPH, any suggestions/remedies for this??

ANSWER: The slipons you installed, are they straight pipes or do they have mufflers in them?
Mike

---------- FOLLOW-UP ----------

QUESTION: straight pipes w/baffles

Answer
What is happening is with the long pipes you are not getting enough back pressure on the exhaust system, even though you have baffles in the pipes. When you dont have enough back pressure you get popping.
You might try some torque cones which cannect to the pipe where the pipe attaches to the head. this will add more back pressure to the exhaust
Happy holidays
Mike