we have a bit of it - nothing really explosive.
generally it seems to go away after the car is warmed up.
what sorts of things can cause this?
improper air/fuel mixture?
moisture in exhaust?
leak in exhaust?
timing?
our gasoline is good not old and we have new spark plugs installed.
i would appreciate suggestions on where to start investigation.
Start at timing.
And then leaky exhaust near manifold or cracked exhaust manifold.
The exhaust manifold bolts like to unscrew themselves, so check those too.
Way too rich a choke can cause it to cook off in the cat. I've done that before.
My Olds Omega used to do that, turned out to be a bad choke.
As was said, could be choke - too rich or lean for the engine temp until it warms up.