u/DopeyParrot

So I recently changed the O2 Upstream sensor on my Focus. The bung, I think it's called, was pretty stripped unfortunately. I used a thread chaser and got the new sensor in but it's not super tight, I can feel as I'm tightening it it's going to slip. Would the P2251 engine code be caused by not having a tight seal, like air getting in? Or is the sensor itself bad?

I was thinking to use some JB Weld on the outside to seal it. Not sure if that would work?