Well a pop in the exhaust could be a lean misfire, could be a rich condition firing in the exhaust, could be a header leak, could be an ignition issue.
If you think it is EFI related, adjust your cruse target to 13.5, see what it does. Then 14.5, see what it does, if no change either way, it's not the tune, if worse one way and better another than it tells you what to do next. However, if you do consider going leaner than 14.5 on cruise, be careful
Sounded real nice to me though, I didn't hear the popping and it didn't look too lean.