Rusted Exhaust Bolts - solution?
 

So I was knee deep in some car work today. (2010 TSX fwiw). And I wanted to install this new RV-6 Downpipe/Pre-cat delete set up. So I jack up the car after loosening everything in the engine bay I needed to.

The next step was to get under the car and release the splashguard to get to the core components of the exhaust. So I get under there.... and previous owner just did away with the splashguard. OK, great that saves me 20 minutes of unbolting and bolting this plastic back on afterwards. So I went moving forward.

Well as luck would have it I went to unbolt the primary catalytic converter, then turn my attention to these spring nuts as well (the bolts at the header came off easily, these were the last two areas of unbolting needed).
https://cimg0.ibsrv.net/gimg/acurazi...d2d5ba4890.jpg
https://cimg2.ibsrv.net/gimg/acurazi...4da4acf4f6.jpg

I tried to get the nuts from the first picture off after soaking WD-40 on it. 14mm. Wouldn't budge. Ended up stripping the crappy socket I had on there. Slapped on another one. Stripped it again. Went to hardware store and got top of the line sockets after spraying more WD-40. Came back 45 minutes later. Got a breaker bar on the socket wrench. And pushed and pushed and just would not move a millimeter.

So hung my head in defeat and replaced all the stuff I had taken off and had to brainstorm for a solution.

So essentially these nuts and bolts have taken the brunt of the undercarriage elements for God knows how long without the splashguard. I've read solutions for rusted bolts before and want some opinions.

1. Take it to a muffler shop and offer them some $ to just loosen the bolts I need to remove. Just loosen them, but keep them on. So I can drive it home and finish the install myself. The only issue I have is what if they have to cut off the bolts and they don't have adequate replacements?

2. Take it to an Acura dealership and offer them the same deal, only advantage I can see to this is that if they have to cut the bolts they most likely will have correct replacements if it comes to that? Only downside I can see is them not having tools to cut the bolts if it needs to be done.

3. Get a blowtorch, rent an impact wrench, try a bunch of home remedies again and hope that it works

These things are ridiculously stuck I'm surprised a socket didn't explode

(of note, after the new pipe is installed the spring bolts go in the garbage as the new piece is all one pipe from header to cat... also if the RV6 rep has a problem with me posting their actual manual photos let me know)

Thanks you guys, really put a damper on my weekend for now

Torches are usually the easiest. I like having a real o/a kit though, it's easier to focus the flame with a welding tip. That is a bit of an investment for one job though. I know the new fancy mechanics have inductive bolt thingies so if your mechanic has one of those it would be pretty easy for them to loosen it for you.

Impact wrench with a good quality impact socket.

I was thinking an angle grinder (pictured above) and a good drill with some metal chewing bits. A little bit of time and a lot of satisfaction.

1. WD-40 doesn't do jack. You want to use a good penetrating oil like PB Blaster.

Yeah I asked my dad (was our weekend project) if he had rust penetrant "oh yeah don't worry I have some WD-40"... didn't have the heart to tell him that's not the same

Although glad we had it on hand for the new air-intake, some of the rubber pieces sliding onto metal components was like a wrestling match

Have heard good things about PB Blaster

Well I've decided to take it to a shop tomorrow to get them loosened; I'm only in town until Wednesday and don't have time to be dicking around buying new solvents, renting tools, buying tools hoping these things come off. Just going to call around and ask how much each shop charges for loosening it. Figured at most if I did it myself I'd need to rent an impact wrench (have air compressor) and price for that, and other difficulties encountered would be worth $50 so if the shop charges me $100-150 for the task paying a cost differential of $50-100 or so is not ideal but not going to lose sleep over it.

You can also try freezing it with upside down canned air. The hope being that the contracting of the metal will break some of the rust free. I've never done it though, just read about it on forums.

Get the nuts a bright cherry red or orange in color (almost white but not quite) and use a 6 point socket. It will squeak but you'll save the stud. Of course you need an oxy-acetylene torch.

I've done this on nuts that hold the manifold to aluminum cylinder heads where you cannot afford to snap the stud.

Using brute force will most likely screw things up.

And WD 40 is good for one thing...removing tar stains. Useless for anything else.

Also pretty good at stopping squeaking door hinges...