This might be a stupid idea but, in a nutshell, take all R123a components from a 94, 95, or 96 and install them in my 91. Possible or no? The A/C in my 91 hasn't worked in years and leaks like a sieve. I thought instead of replacing most everything with 91 parts that I would do it with the R134 parts instead. Labor wise it would be about the same for me but now I would have an up to date system. My worry is the ECU and whatever else senses pressure and such in the system would not be compatible with the new hardware. Have any of you done a complete conversion rather than a freon changeover? FEOA search pulled up plenty of freon retrofitting but nothing about the full system exchange.