why does my car die n wont start if i dont give it gas on 1997 Cadillac Catera

i just changed the spark plugs n it started doing this

Asked by for the 1997 Cadillac Catera
did you leave anything unhooked? double ck your work
no every thing is all hooked up i figured out the problem it was my sensor i think its called throttle sensor thang n now im haveing a problem with it getting going from a stop it takes a few secs to get up n go but after that it runs fine untill my front end starts shacking really bad do u have any ideas bouth that ?