Home >> Audi >> 2021 >> A4 Quattro Premium Plus, 2.0L Eng VIN B >> Repair and Diagnosis >> Heating, Ventilation & A/C (HVAC) >> A/C Compressor >> Air Conditioning (Refrigerant R1234YF Servicing) (2 Of 2) >> 87 Air Conditioning >> Refrigerant Circuit >> Possible Concerns >> Odor From The Heater And A/C Unit >> Notes