Tips for removing corroded nuts?

You say you used locknuts, but those don't look like true mechanical locknuts. Are they nylocks? Or did you put lock washers under regular nuts?

 

Yes, I used nuts like the one above (I think this is the precise one from Home Depot that I used). I avoided lock nuts with nylon because of the heat that the exhaust would generate.

 

Couldn't see that on my phone

The one I got at the dealer were the blackened type with the very narrow malleable tops.

 

Those style are called top locks. They are my perfered in general.
I would definitely get some anti seeze and do one at a time. Will save your ass next time u need to do it.
Plus it's good to have around for lug nuts and such.
Good job with the patients.

 

When i had to replace my front O2 sensor one of the studs broke off inside, i had cut off the flange and drill, the part that really sucked was my super expensive hardend drill bit broke off inside too and that was a bitch to drill out.

edit: Also AC Delco rust penetrant is the best stuff to use alot of people like to use PB Blaster but AC Delcos stuff is way better

 

I almost gave up and brought mine into a shop....but good thing I gave it one last go. After a few days of PB blaster I was able to use a small pair of vice grips and those nuts came off like butter!

Unfortunately I didnt have replacement nuts and had to use cheapo (not stainless) nuts. Hope they hold up! Maybe coating them with something will keep them in decent shape?