Hey I stripped the bolt on my header when trying to replace my stock cats...the bolt itself can be taken out of the manifold and tapped or replaced. We had an impact wrench, a deep socket, and a loooong extension, but if you spray some penetrator you should be able to muscle it out and then work on a bench to ge it right. I think there is a hex under the threads that you can get to with a deep socket...

-Darth

 

if it is just the nut that is stripped connecting the stock exhaust manifold to the cat and not a bolt head. Then you can simply crack the nut and then back the bolt out with a slight tap of a hammer. You can get what looks like a standard box/open wrench that goes around the nut and has a harden spade that is cranked in which splits the nut.

Then just find a nut to replace it when you reinstall or if your headers came with new hardware for the mount to the cat use the new hardware.

 

Thanks man!