Catalytic Converter Removal Question

Sorry for the crappy pic but, not sure what I'm getting into here. Trying to remove driver side lower cat. Two flange studs with nuts, one visible in photo. There have been several days of WD-40 soaking in advance of this.



Appears to be a stud with nut retainer on it. I can't break the nut loose with a socket.

Before I try an impact, I have 2 questions:

1. If (that's if...) the nut comes off, should the cat slide off the stud or, does it need to come out too?

2. Likelihood of breaking the stud while removing it and/or nut?

 

PB Blaster may be worth a try too. I've had a couple times where WD40 wasn't cutting it but soaking with PB Blaster did the trick to loosen bolts up, so now I just use it from the start instead of WD40 since it seems to handle rust lockup better.

 

Not a bad idea, that shit works! We used to call it Peanut Butter blaster!

I wanted to use Kroil but, mine is in a can and I can't dribble it uphill

 

Yeah PBB is pretty great for minor rust removal too, I use it to help clean rust off surfaces before painting and it seems like it's better at seeping into joints and gaps if you use one of the foamy cans too. Only downside is it's got quite the odor but I guess that's a good thing to discourage using it inside unless you really need to.

 

I don't ordinarily work on cars.
I found a breaker bar and they all came loose. I'm all good.

 

May I ask, why are you taking them off?

 

Penetrating fluid doesnt like to work upside down, also it doesnt make a bolt any less tight.

Heat is the answer, a small propane or butane torch to heat it up stupid hot first is the best thing to do.

 

Doing an exhaust re-route myself.
I want to weld in stainless to the existing stainless re-using the existing flanges instead of muffler guy permanently MIG welding carbon pipe in there. I'm a welder and can fit/weld the new section but, I'm not much of an auto mechanic.

I want to remove the cat so I can weld this on my workbench and then bolt everything back in. Welding under the truck without a lift sucks.

 

You're probably not too far from Perryville. I'm sure there's a few guys in there that could tell you how to get them off real quick.