for a while my lumina wouldnt take gas without the key on. now it jumps around at 45 or so, and when i try to stop it lurches forward and tries to pull away from the brakes. anyone know what might be wrong with it?:uhoh:

If the check engine light is on, have it scanned or pul the codes and post here. It will help us in further diagnosis. If no check engine light is on, it sounds like a problem with the vapor recovery system.

that's what i thought...where is the vent and can i clean it out with anything? or do i have to replace it?

I believe the tank vent is electronic, so it's not cleanable. You may check the vent tube at the filler neck to see if it's kinked or collapsed.