Well like the first answer says, you can take the rear seats out and it is underneath the seat. You CAN change it through this plate. I have changed mine this way and so have plenty of my friends. As far as the problems it could cause, like the other guy said it could turn off, not start, or even make your car run lean. which means your car might be getting some fuel but not enough, which in turn risks the possibility of blowing the motor. If you think you have a problem with your fuel then you should also check the injectors and the filter as well. It might even be just a filter problem. Well good luck and hope this was a little helpful.