Compressor Oil

WARNING: This page is about a different car, the 2003 Subaru Impreza. However, it is still accessible from the selected car via links, so may be relevant.

HFC-134a compressor oil has no compatibility with that for R12 system.
Use only the manufacturer-authorized compressor oil for the HFC-134a system; only use DH-PR.
Do not mix multiple compressor oils.
If HFC-12 compressor oil is used in a HFC-134a A/C system, the compressor may become stuck due to poor lubrication, or the refrigerant may leak due to swelling of rubber parts.

On the other hand, if HFC-134a compressor oil is used in a HFC-12 A/C system, the durability of the A/C system will be lowered.
HFC-134a compressor oil is very hygroscopic. When replacing or installing/removing A/C parts, immediately isolate the oil from the atmosphere using a plug or tape. In order to avoid moisture, store the oil in a container with its cap tightly closed.