2012 G37

Just going to keep it sweet and simple .. what’s the trick to getting that top driver side catalytic converter bolt out?
Got a shop full of tools and it’s leaving us BEAT. Feels like it’s welded shut lol

I feel like we’ve tried everything. From top and bottom no luck at all. At the point where I’m just going to cut the dang thing out.

Any tips is very much appreciated

 

Assuming you exhausted all means of trying to use air tools, PB blaster, extensions, etc...You may have to do what I did and cut the stud side where the bolt is stuck on as flush to the flange as you can. Proceed to do the same on the other side. I used Diablo metal cutting blades to make the job easier. Then use an acetylene torch to punch out (melt) what remains of the stud still located in the flange. Give both sides of the flange a quick hit with a sanding/grinder to flatten them before installing your new cats/test pipes/HFCs.

You could also try a left handed drill bit after cutting the nut off the stud (to see if you can back it out) but in my experience, the stud was so tight/rusted on there that the attempt was futile.

I tried the drilling out option first and wish I would've just skipped to torching it. Took all of 20 minutes after struggling for 45 minutes drilling the stud. Just be conscientious of the O2 sensor located behind the stud if you decide to torch it out.

 

To ensure that I was making a solid connection on the bolt, I disconnected the steering shaft (370, so don't know how different for you).

If you're past that for sure, the above is the way to go.

 

Torch it and break it slowly or let it soak in pb blaster

 

I hear around here that there is a 50/50 mix of ATF and acetone. Mix those two together in a metal can (acetone will eat through plastic//rubber) and spray on. From those who have tried it on their dreaded cat bolt, they say its leaps and bounds better than pb blaster. It may also help to do more than one application after waiting a bit

 

I tried the mixture but I believe pending where you live, and how bad the rust is, the mixture won't help you much. If they are stuck, heat is your best friend.

 

Five years ago, I was in the shop while my old mechanic was installing Fast Intentions RHFCs. He struggled a whole lot with that bolt and finally gave up, using the torch to cut the corner off the flange on the OEM cat. So I still have the cats up in the attic somewhere, but if they ever go back on the car (they won't), I'd have to have a new flange welded on.

Probably not the best story to hear, but there it is.