Hi, I have a Pontiac Sunfire ’99 automatic that has the following
problem: when I drive it on the highway at constant speed it starts to
vibrate and the revs start to get lower and higher also, its like the
car is going to turn off... if I push the gas pedal or lift my foot
from it the problem goes away... After driving on the highway the
problem persist in the city, specially when trying to start from a
standing position... when the car is stopped or in neutral it also
goes away... I already changed the fuel filter, the spark plugs and
cleaned the injectors... somebody told me to change the wire set but I
want to hear suggestions from somebody else...

Thanks!

JSM