Performed AC diagnostic on 2014 Goodman condensing unit. Upon my diagnostic there were a few points of concerns that were addressed. Found that system was very low on 410 a refrigerant charge and was previously charged up by two other companies about twice. Added refrigerant charge to find out that the metering device is a piston although the piston may be the wrong size or nothing at all because I had zero sub cooling which is not a good indication it may mean that this coil is flooding. Also dropped in a refrigerant leak dye To confirm location of leak in approximately one month. 1. System extremely low on 410 a charge due to refrigeration leak. 2. Previous company swapped out condensing coil but kept old evaporator coil with piston metering device. 3. Piston metering device may be wrong size or may not contain any piston within valve due to the low sub cooling I observed on my gauges. 4. Injected refrigerant leak dye to pinpoint exact location of leak Recommendations- 1. Locate lea