Arrived to investigate weird smell coming from system. Homeowner states smell is only present when running cooling mode and has a sweet smell. Inspected ductwork, filter, flushed drain line and tested heating operation. Checked gas pressures and adjusted to manufacture specifications. Tested electrical components, took amp draws and verified system operation from thermostat. Inspected outdoor unit electrical, refrigerant levels and checked condenser coil overall condition. Opened evaporator coil to check for any potential refrigerant leaks. TXV threaded nut showed small bubbles after spraying with leak detector. Tighten up nut to txv and checked again for any leaks. Did not have any bubbles show up and electronic leak detector did not pick anything up. Evaporator coil has insulation clogging part of evaporator and recommended evaporator coil cleaning. Having a UV system would benefit indoor air quality as well as the added benefit of helping keep equipment cleanliness. Condenser coil i