Did I break my O2 sensor?
 

I have a cat bypass on the way, so in prep, I removed the cat heat shield yesterday. After removing the shield, I noticed the O2 sensor looked rusted in place, so I put some pen. oil on it, and took a long wrench to it, and it came loose. I tightened it back up thinking I could drive the car w/o the shield until I install the bypass. Well, this morning when I drove the car, it performed normal until it was fully warmed up, then it hesitated badly between idle and 3000 rpms. After hitting 3000, it acted normal and felt like I had a turbo kicking in (this is an '85 carrera...not turbo)

The only thing I have messed with is the O2 sensor. Is this the type of reaction I should expect if the O2 sensor is not working? I must have messed it up when I loosened it. Does anyone have any ideas?

I wonder if penatrating oil can damage these sensors?
-Chris