fuel manager

[fxnytro1050]

Installed a ultra Q silencer at about 350 miles. Now I have about 2400 miles racked up and sense I installed it, it kinda sounds different(i thought it was just broke in or whatever) and it seems like im using more mpg. Plus its a little backfire every now and then plus a little hesitation. Not much but just enough for me to know. Seems to be running rich atleast thats what i think.
Id like to get a fuel manager to make sure but just wondering whats the bestbuy for my buck kinda thing.