Oil temp sensor

[02PowerStrokeFord]

When I bought my truck it came with a check engine light. The guy pointed out the oil temp sensor to show it was broken off. The truck ran great. Recently the truck died and would not restart. The only code it threw was the oil temp. So I replaced the sensor and topped off oil as i was several quarts low. It eventually started. Now when it starts it blows a massive amount of white smoke, then eventually starts running very strange with a very high idle. Finally after a few minutes of driving it throws the same code again and starts to run fine.

I put in another sensor to make sure the first wasn't defective. Any ideas?
1999 350 4X4 205,000miles 6spd