too lean ?

Had some really nice weather yesterday, got the fish out and played w/ it for a while . I leaned the fast 2.0 f.inj. down a hair more at cruise and now its popping out the mufflers quite a bit when descelerating, but doesn`t rattle and runs great , DID I GO TOO LEAN ??
Also discovered my rings aren't seated yet.

It would be good to know what A/F you're targeting?

During Decel its not uncommon to turn the injectors off completely, so you really cant go "too lean" during Decel