What could make your car still sputter after a full tune up?

WHO DID THE TUNE UP? DID YOU HAVE IT DONE OR DID YOU DO IT YOURSELF?COULD BE 100 THINGS. A TUNE UP TO ME MEANS NEW PLUGS NEW WIRES NEW DISTRIBUTER CAP IF IT HAS ONE AND ROTOR CAP,NEW AIR FILTER CHECKING THE TIMEING AND ALSO RUN A DIAGNOSTIC CHECK ON THE ENGINE SENSORS, AN OIL AND FILTER CHANGE AND A GREASE JOB WHILE YOUR AT IT. DO YOURSELF A FAVOR AND TAKE IT TO YOUR NEAREST AUTO STORE , LIKE AUTO ZONE AND ASK THEM TO PUT A DIAGNOSTIC READER ON YOUR COMPUTER PLUG AND TELL YOU IF YOU HAVE ANY BAD SENSORS, ITS FREE!!! AND IF YOU DO HAVE SOMETHING BAD THEY WILL TELL YOU WHAT IT IS THEN JUST REPLACE IT OR HAVE IT REPLACED. GOOD LUCK