On 1 Aug 2018 21:41:29 GMT, Bob F wrote:

> I'm no expert on this particular situation, but perhaps a helicoil would
> solve it easily.

I guess it can't hurt.
I can contact Denso to figure out the thread pitch for their O2 sensors.

I was thinking of cleaning up the threads, but they look really bad.
How on earth can ANYONE do that to a bunch of threads?

What did they do?
It's not even hard to get to ... it's right there ... in front.