My 96 has a leak that I cannot chase down. I can fill the system with freon and will leak out by 5 or 6 days. I have tried two different sniffers, but no luck. I have been reading that the evaporators are a known problem. If I am correct, you have to remove the dash to get to it, just like the heater core. Is there an access hole where I can stick the sniffer in and determine if it is the evaporator leaking?