NO
It depends on the year of the car. From 1994 on, R134a refrigerant is used. Prior to that, they used R12 refrigerant (Freon). R134a is technically not "Freon". Be alert, however, as many older cars (like my 1986 Camry) have been retro-fitted with R134a systems, and can no longer accept Freon, as the two refrigerants are not compatible.
No r404a is not compatible with r409a, r134a and 404a use the same lubricates and are compatible but r409a use a different lub making them incompatible
There were some R134a units in 1992, but they were not the norm. Most likely, you have an R12 unit, which requires retrofitting in order to be compatible with R134a.
R134a Freon is an oxymoron, Freon is R12 but the answer is yes, a subtle 'sweetish' odor
In order to remain compatible you should use the same type of freon that is in the system already. If the system has not been converted to R134a it would have R12 in it. R12 is much less used now and more expensive than R134a. You might want to consider having it converted to R134a If it has been converted to use R134a then use that freon.
R134a
R134a freon...................
Freon is a brand name. It uses R134a refrigerant.
R134a
R134a is the only freon for cars after 1994. Earlier cars can be retrofitted to R134a.
it takes r134a freon