Engine Flutters under hard acceleration

Just changed plugs in my 2002 V6 Camaro and it runs fine. I noticed it Flutters under hard acceleration from a standing start. Any ideas?

you know i have the same problem i had missfireon number 5. changed plugs and wirers no change took and had coil and inj module check good. change number 3 injector to number 5. now waiting to see what check engine light says. someone told me might be intake gasket.