Hey guys, when I installed my X pipe i found that the stock one was only held with 1 nut on each side. When i was going to remove it i found out the nut on the passenger side was rounded out.
I couldn't get a grinder or and cutting tool in that small gap. So i chiseled it off. Took about 4 hours of stop and go to finally break the nut off. Question is that the stock stud was a 10mm thread. I was thinking of running a die and hopefully saving the threads (times i missed or moved messed up some threads). OR should I run a smaller size thread like 3/8 or 9mm? Is this header stud removable? Any input will help. Not looking forward to it but I hate having that shitty sounding exhaust leak.
The stock manifold studs are in fact removable. I removed mine with a good amount of PB blaster and a hammer. I'd spray PB blaster on it, wack it with a hammer (carefully not to mess up the stud too bad), PB blast it again, let it soak for 20 minutes, wack it with a hammer....you get the idea. Once I did that a few times I easily removed the factory studs with a stud remover tool from amazon. I used a kit similar to this:
MY issue is I messed up the thread on the manifold by threading in the wrong size stud after I removed the factory ones. To rememdy this, I ran long grade 8 bolt that's smaller then factory and created a nut/bolt set up.
Being that the nut was the thing seized and the stud is still in tact, you should be able to remove it with PB blaster, hammer, patience, and the remove kit I linked. Don't go cheap on the stud removal tool (learned that the hard way trying one I got at harbor freight).
EDIT: I just noticed you said it was the PASSENGER side. On the passenger side I removed the studs and used bolts. I thread the bolts from the bottom up (bolt head holds up the mid pipe and threads into the manifold). This works amazing tightening to 30 ft/lbs so you dont kill the crush gasket in there.
On the driver side (ball and socket type connection) I created my own nut and bolt set up as that's the side I screwed up the threads on the manifold.
If this doesn't make sense, let me know and I'll snap pictures from under the car.