sputtering enging when accelerating on 1997 Pontiac Bonneville

I have a slight sputtering when I first take off ,I first though bad gas and so I put better gas in it an it seemed to help some but still sputters just enough to aggrivate.At speeds of 25mph it seems to run fine but again take off it sputters ?Where do I look first ?

Is the check engine light on? Codes stored in the Powertrain control module would be the first place to look. You may also have an engine misfire caused by the secondary ignition (spark plugs, plug wires, or ignition coil). Road testing your car with a qualified technician may help isolate the cause of your fault.