Going off of the umpteen posts you put elsewhere, you put on a decat exhaust.
Without the cat, the air being injected into the motor via the pair valve system has no where to burn up so it burns up in your canister; giving you the crackling you're experiencing. You can help get rid of that by installing block off plates (PM Mike AKA RidersDiscount on the forums here and he'll set you up with a set of Graves plates) or you can install the $2 rubber plug from Brocks (http://www.brocksperformance.com/Bla...32648+C10.aspx
). This caps off the air from the airbox going to the pair valve so you have no air injection and seals off the airbox so there is no pressure loss at speed. It's cheap and a 5 minute install. After doing that, if you still have popping you're probably going to need to have the bike tuned.
Regarding the fueling... you can't just throw a Power Commander on the bike and have it magically fix the problems. It comes with a "Zero Map" so there is essentially no fueling changes. You can download the base maps they have on their websites, but those are only going to get you so far. Ideally a custom tune is the way to go. Here is their base map... you need to use the American version since your bike has a restricted ECU. Download this file, connect to your power commander and load it up: http://www.powercommander.com/downlo...17-028-008.pvm
(For NA Bikes, Yoshi R77 3/4 slip on /w stock filter).
What can be done, is the ECU can be flashed and help put in fueling that way for your slip on to help clean things up and somewhat help stop the decel popping. There is a guy on this board, that does the ECU flashes for cheap (hint, it's me): https://www.zx-10r.net/forum/showthread.php?t=218786
After that, you can have the bike ran on the dyno to see where your air fuel is at and make the determination whether to have fine tuning done to optimize the bike. It is something I recommend to everyone I flash.