Stange male torx but on front catalytic converters exhaust flange 2003 Tacoma

I’m trying to replace my catalytic converters and went to get started expecting an easy job. The first thing I ran into is a weird nut (on the studs that hold the front cat onto the headers) on top of the 14 mm nut. It fits an E8 socket but when I went to remove the first one I rolled the nut without almost no force. Does anyone know about these or a good way to get them off. If not my current plan is to slice it in half with a Dremel

 

What happened when the you turned the nut? The e-torx is the stud.
You will need to remove the nut first, or torch the flange till it expends and the the stud can move.

 

There are sockets for those. Can’t remember off the top of my head what they are called (maybe inverted torx), but I believe a 12 pt socket, or the craftsman professional end wrenches should take them off. I had something similar for the front differential extension tube on my 2004. My craftsman set had something that matched those perfectly.

 

Its a security bit. Trying to make it harder for someone to steal your cat. Even though most thieves just use a sawzall.

 

I think you guys are looking too far into the problem. It's just a simple nut that needs to come off.

AFTER the nut comes off you can unscrew that e-torx and remove that stud if that's what you are trying to accomplish.

Spray it down and hit it with an impact, it looks like it's in pretty good shape.

 

As others have said, that star is the end of a stud. You only need to remove the six sided nut, the stud stays in place. This is what it looks like...

 

M10x1.25 stud and a M10 x1.25 stainless lock nut

I have bunch of those The male Torx is to set the stud rather then two nuts method Just zip it in with a impact

Great for exhaust manifolds as well Most Toyota dealers stock both pieces.