>...my a/c charge had to be sacrificed...
It's a good idea to recharge so the seals don't dry out. Coolant
carries oil in the system, and periodically running the a/c throughout
the year maintains pliability of the seals. Conversions? Check out the
unsanctioned information at http://www.vettenet.org/acfaq.txt
Just for reference, how much was the O2 sensor?
--Gary
('86's:5ks&5ktq+'87CGT)