My 97 Firebird 3.8L makes a popping noise upon acceleration. Only in D or R, not in P or N. It seems to comming from the left side of engine. Any solutions?

detonation maybe? any chance youre getting crappy gas? are you noticing any loss in performance?

maybe an ehaust leak that opens when the motor moves

one thing that you might check is your u joints, that pop in revese and drive on inital acceleration is usally a u- joint.