1997 Grand Marquis Cylinder 4 misfire bank1 sensor 1, Lack of heated oxygen sensor

1997 grand marquis Code read cylinder 4 misfire bank1 sensor 1, Lack of heated oxygen sensor
The car runs but stalls when accelerating, I recently had all spark plugs and the engine coils replaced thinking this would fix the problem but it did not.

The only other thing I noticed was that the muffler was hanging. I tied it up to not hang. Could this be the cause of it stalling when accelerating?