too lean ?

Jus thinking out loud here,
I have heard that when you go too lean, the fuel cannot always find oxygen to react with and just passes thru the cycle unburned.
So;more thinking;
how about changing the the Ais air to base air ratio, to get the throttles open a lil more during decel.
or, if that popping is from the fuel charge still burning when it enters the pipes,then how about adding some advance in the high-vacuum decel mode, to start the fire a lil earlier.