Hi Garrick,
I am glad to hear that at least SOMEONE else out there also had problems with this sensor replacement. We kept wondering what we were missing, and kept saying "there has got to be a better way". A real son of a gun! We used the O2 sensor socket adapted down to 3/8" just as you did to break the orginal lose, then found a large open ended 7/8 wrench worked best to tighten the thing down. (sounds easy, but it is very tedious getting onto the sensor) I didnt have any codes, but noticed a definite mpg decrease the last 3 times I checked mileage. I am curious to see if this corrects that.
Good Luck,
Tim
