If you actually just plug the PFC directly in your car will start no problems, just won't be able to drive it very far. You can drive around with the base tune, but I wouldn't be fanging it or anything. When I got it installed, I had a tank of Vortex 98 + Octane booster to make sure it wouldn't ping too hard. Driving back home and then off to the tuners the next day, keeping the revs and throttle position low. I had problems with a granny in her old school beetle, and I must admit she had me at every traffic light :D