Old oxygen sensor removal

This is exactly why I use Vice grip pliers to remove the studs, rusty nut and all. New studs and nuts

 

Wow I didn't think that was even an option. I thought the studs were welded into there. I didn't see a way to remove them.

Back to work on it tomorrow... The base under the old gasket was rough with rusting, and I have some rust dissolver doing its thing on it, then I'll see if I can sand it smooth without getting rust dust into the exhaust, before installing the new stuff.

 

The studs are threaded into the exhaust bung. You can (and should) remove and replace both of them in addition to the sensor. At the very least, you need to get a die, and re thread that existing stud to accept a new bolt, otherwise you're just going to cause yourself more grief. Also as far as the sensors are concerned, ONLY get denso sensors, anything else is asking for trouble.

 

Update: I think the job's done!

Good call on the rethreading die. After that the new nuts went on pretty easily. The nut splitter I think helped a lot, and the locking pliers were critical.

Cleared the codes, drive 60 miles, around 20mpg, seems ok, no codes yet! I'm surprised I succeeded in the end, assuming it holds up without a code for a few days. I don't think I could have done it without the help here.

I'm going to hit the underside with degreaser. I had no idea that place was a mess. I probably should also bend back into place what I think is a heat shield that was in my way.