When did R134a become standard in the Taurus?

A 1994 and later Ford Taurus will have a factory, refrigerant (R134a) 134a system. In mid 1992 all vehicles produced for delivery in the United States were required under Federal law to have this type of system. Occassionally, but rarely, one will find a late 1992 or early 1993 system that still has refrigerant (R12) 12 fittings. But this is the exception rather than the rule and it is unheard of (virtually) for anything later than 1993 to have anything other than an R134a ayatem. Of course, it is easy to determine which system your Explorer has by checking the service fittings (the place where refrigerant service manifold guages hook up). Although as of last count there were over seventy (that's right!) different refrigerants on the market (all requiring [technically by law] their own exclusively distinct service fittings) there are only two refrigerants that (a) have ever been used by ALL (U.S.) automobile manufacturers and (b) have ever been approved by BOTH the EPA and all (U.S.) automobile manufacturers (concurrently). These are R12 and R134a. If the service fittings on your vehicle are 1/4 inch, male flare fittings, you have an R12 system. If the fittings on your vehicle have no threads and resemble the type of fitting used on modern day air compressor (an air 'chuck' type fitting) then you have an R134a fitting. If you have 'air chuck' type fittings attached over 1/4 inch male flare fittings, you have a system that has been converted from R12 to R134a (keep in mind that the specially designated fittings for some alternative refrigerants bear similar resemblence to R134a fittings, but R134a guages will not attach to them). Also, keep in mind two things. Refrigerants that contain ANY amount of flammable substance(s) (such as Freeze12, HCFC12, AutoCool and others) are illegal in most states. Refrigerants other than R12 and R134a void warranty on most parts produced by most manufacturers (and, yes, they do test, and yes, they can tell).