Help removing exhaust - 850 -97

DennisCA · Post by **DennisCA** » 25 Aug 2026, 02:30

I got these 4 bastard bolts I need to undo so I can remove the cat and weld it. I have very bad access to some of the bolts and they look rusted as heck, they don't even feel like they are the same size anymore, the same wrench is too big for one but fits on another. I assume it's just rusted so much.

I am not sure is it better to remove the manifold itself? Not sure there's enough room to get it all out if I do that though.

Post by **scot850** » 25 Aug 2026, 08:42

When they are that badly rusted you are probably better removing the manifold. The caution here is that you could break manifold studs into the head.

Another option is to cut the flexi hose and replace that after welding the cat.

Last option is to keep soaking the bolts with a penetrating oil and let the engine heat cycle the bolts for a week and see if that helps.

An induction coil would be a nice to have option.

Lastly, there are times to ask for help, and if you have a good muffler/exhaust shop to ask them to take a look.

Good Luck!

Neil.

DennisCA · Post by **DennisCA** » 25 Aug 2026, 23:00

I am not driving the car right now, it's taken out of traffic. My goal is to have it driving again in late september. So heat soaking like that isn't gonna work unfortunately. If I could get good enough access there's the possibility of welding on it of course, welding nuts on the bolts tend to help, access is the real issue though.

I ordered a new cat-back exhaust (stainless 2.5" system) and wanted to remove the cat so I can weld on it because there's some rust on the pipe where it joins the cat itself.

Maybe I could do what I did with another car, I cut the pipe in front of the cat and put it back using a clamp fitting. It worked well on that car, just need to find a straight section to cut. That would mean making another joint in the exhaust though which I don't like. But I don't like the idea of dealing with broken studs right now...

hydar123213 · Post by **hydar123213** » 26 Aug 2026, 01:41

For me 3/4 were removable with spiral bolt extractor sockets, the 4th one we cut with a dremel. After cutting the nut (and also the stud) the rest of the stud in the header could be threaded out with a "Swedish pipe wrench" and replaced (this was done later and out of the car though, not sure you could fit the wrench on it in the car), another option we didn't know about at the time was a nut splitter. For access/leverage they could all be reached with either a long extension from under the car or a long ratchet with a flex head from above.

Before that I had a band type clamp on the cat pipe which did not work, the clamp held tight when installed each time but the cat would shake loose from the clamp after a week or so since the clamp in that location had to hold up the weight of the cat. If you weld in the clamp it would probably work but I ended up just replacing the whole cat as it was so badly rusted that one side snapped off completely while sawing the other side outside the car. Also the clamp made the pipe longer so I had to remove the heatshield under the cat to prevent it from hitting that.

DennisCA · Post by **DennisCA** » 27 Aug 2026, 23:47

This problem got me to punch in a final order of some parts, been assembling for quite a while but never got to the finish line, but I will have an oxy-propane setup soon to go at the bolts with. Actually it's an oxy-acetylene X11 torch (my dads), but you can run it with propane on the larger welding nozzles and also the cutting attachment if you get propane tips for it. In the future I might go over to OA instead, but maybe not.