You normally get rid of popping on deceleration by richening things up a bit.
You stated that you have TORS on your bike. My 03 had TORS and no mods to the intake. It popped like crazy on decel. I removed the AI so it would have been just like your 04. I'm assuming the snorkels are still in place under the seat. If you leave those in place, I'd increase the main jet size from 120 (usually stock on an 03/04) to 125. If you want to remove the snorkels in the intake box, you will need at least a 132 to 135. I ran 135 main jets. I then added 2 shims to the needles and eventually switched them out to needles out of an early Thunderbird which got rid of a mid range hesitation/flat spot. Next, pull the idle adjustment screw caps and open the screws up a quarter turn at a time. You will be amazed at the increase in performance. These mods will help with decel popping. You could start with the easiest first by just adjusting the idle mixture screws but you would be missing out on the fun factor.
The second way to get rid of popping is to disconnect the Throttle Position Sensor (TPS). It is a bast--d to unplug. Do not unscrew it from the carb but unplug the three pin connector. The cable comes from the right hand carb. This change will not noticeably affect the performance of the bike but virtually get rid of the popping. If you perform a search at least 5 years ago, you will find the proof that it works.
