Today on my lunch break my svt started shaking, but not bad. I get off work and it does it again like it miss fires at low rpms. Also does it at high but not as bad and i changed the plugs and wires bout 5 months ago. Could it b the coil pack or no that would just go out? The car starts fine thoe so i have noidea where to start. Maybe fuel injecter? Also i have no check engine light. Plz help..!!!!!