1994 Bronco 4X4 full size 5.8

One very cold morning I started it and moved it forward and shut it off. Running rough. A while later I went to start it and it wouldn;t start. Smelled gas afnd it was flooded. Checked code and cod#173 came up and also coolant senser out of range. I changed the plugs and the coolant sensor, intake sensor, it started and ran ok for about a month but still surging between 100-300 rpm. NOt all the time. Then one morning it happened again. It ran for about three to four minutes and then stalled again. Flooded, smell gas and would not start. So I changed the idle control motor and the coil and the plugs and it started ok but it is still surging very little up and down. When it warms up, code reader says #173 running rich and 412 unable to control rpm during high rpm self test. Im thinking oxygen sensor?