Generally popping on deceleration means you are lean. However in rich situations when you leave it lugging on an extended downshift it can load up with gas and do little explosions on you.
AI makes it lean, if it got a bit better when you took AI off then you just need to increase fuel. That may mean re-jetting, yes. I don't pop much at all with 45 pilots and 130 mains about a turn out on the air fuel mixture.
There is a jetting chart in the tech vault I think.
