[RuffedUpXJ]

High Pressure and low pressure will not allow the system to run. You best bet is to have it vacuumed out and then have them check it in a day and see if there is a leak. After that you can add with the small cans to get it to the right pressures. If you want to do it all on your own then you need the guaged can, or you can rent high side, low side and gauge from AutoZone to watch the pressures. Also get the stock pressures for the car from a manual or whatever.