First, its called freon. Second, have you run some UV die through the system yet? Might be a better alternative to the sniffer. There is nothing in the dash that contains freon. Check the high side (i think its the high one, anyway) fitting (the one on the drivers side above the trans). I had an issue recently where the schrader valve in it was not sealing and did not know it until I removed the cap to stick the gauges on it. Put a little pag on it and pressed it a few times and it sealed up again. Was the cause of my slow leak.
