Well, I live in the salt belt, where everything rusts, including stainless steel. A torch is a mandatory tool for working on cars and trucks.

You know, you could always unbolt the flange on the input side of the convertor , then remove 1 or 2 rubber hangers so the exhaust sits on the ground. This might give you a better angle and more leverage to break the sensor loose. Just a thought.

 

Guys, thanks for your hints. Jim, I can understand why you say heat the converter, not the sensor. One would like the area adjoining the threads to expand and not the sensor itself. In any case, I got the right size adapter for the impact driver and proceeded for another repair session. I tried heat treatment coupled with alternating with breaker bar, combo wrench and hammer and the impact driver with hammer. The bolt simply refused to budge. At this point I've given up and will take it to the shop. I know when I've reached the limits of my capabilities and strength. Again, thanks guys for doing your best to help me out. I learnt a few things along the way.

 

Im not trying to be insult your intelligence but are you sure you are turning it to the left and not the right.

I'm asking because a friend of mine worked on a bolt for a couple weeks and couldn't get it an when I went there to assist it cam right off. Needless to say he was turning it the wrong way. He stated being on the ground got his left and right mixed up. Lol

 

Sean, no offense taken. Thanks for bringing up this possibility because it is a real one. I'm assuming by "left" you mean counterclockwise. I thought about this issue 2 - 3 times during my various attempts and confirmed to myself that I'm going in the correct direction. I do succeed in most repairs. I think that in this case my limitation was the torque/force I was able to exert. My body weight is on the lighter side.

 

I finally took it in to the shop yesterday and they used the oxygen sensor I had purchased from Amazon. I saved on the cost of the part, they'd have charged me almost twice. The service adviser said they use heat to help loosen the bolt (no surprise here). Now the check engine light is gone and the issue is out of the way.

 

Glad to here you got it figured out