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Can I replace my exhaust? (serious rust, pics)

I have a small leak in the flex pipe of a 04 Nissan Sentra, so I’m looking to see what’s the best way to fix it myself. I would replace the flex pipe alone if it had connections to it but it’s part of 1 long piece of the exhaust. I was looking to replace the whole section of exhaust from front to middle of car. But looking at these connections are they able to unscrew off. The end connection I’m able to cut off because there nut & bolt, but the front connection is stud and nut, and the stud is not welded in, was told it can unscrew off.
Looking at the pics is there a chance that it will come off, if so what’s the best way? If the front connection snaps, cutting the studs will that be able to get drilled out? All I got for heat is basically a plumbers torch and heard melting candle wax in threads helps out, but it looks all sealed and coated up, I really would like to remove the whole stud out, is it possible that the threads are so coated that it will unscrew out from that Cat vs the nut coming out threads? I don’t have an impact wrench/drill. What’s the best way to remove it, what are my options?
If cutting out the flex pipe is better I don’t have a welding machine, so can it get clamped in there?

With the limited tools you have, pay someone to repair the exhaust.

I mean, there are nuts that aren’t nuts anymore, and studs that aren’t studs anymore.

Even with the proper equipment, exhaust replacement isn’t all that easy.


Tester is correct. Have a muffler shop do it right.

One more vote for the muffler shop. I have the tools, but I’ll gladly pay someone else for their trouble.

Another vote for the muffler shop. Exhaust work is messy and difficult without a hoist.

My guy is a bend your own pipe place, last work, most exhaust and welded split catalytic less than I could have done for parts from the parts store, lifetime warranty on muffler, had it replaced 5 years later under warranty, $5.00 charge for a muffler clamp.

Let the professionals handle it. It’s a frustrating job dealing with rusted pipes, nuts and bolts.

Make mine another vote for a pro. Pros have the tools and experience to deal with this. You don’t or you wouldn’t have had to ask.
I’d recommend against a chain shop in favor of a reputable independently owned and operated shop.

Another vote for a pro. Like TSM says they have the tools and more importantly the experience.

If you decide to try it yourself anyway, despite the good advice above, be sure to wear good eye protection. There’s lots of dirt and grime and bits of rust and metal that can fall down and find their way into your eyes when working on rusty components like that.

This the OP who several people recommended they fix the exhaust leak at least 6 months ago.

Some jobs just don’t justify the money that might be saved.
Notice the nuts have the flats rusted to the point that no socket will fit it. Also notice the nuts appear to be part of the studs, joined into one from rust.

I have successfully removed nuts and studs like these and worse but I had,
A lift
oxy / mapp gas torch
a plethora of sockets and extensions

Its not worth it, take it to a shop.

@“VOLVO V70”

You’re right . . . ! :smiley:

Talk about a delayed reaction on OP’s part :smirk:

Perhaps in another 6 months time, we’ll hear about the exhaust studs that snapped off :fearful:

I once decided that I would replace the muffler on my 1978 Oldsmobile Cutlass. The muffler was at the rear of the car so I didn’t have to raise the car. I bought a muffler and clamps at NAPA and went to work. I did the job in about 2 hours. The next time the muffler needed to be replaced, I went to an independent exhaust system shop that has been in business for at least 60 years. The shop did the job in less than 10 minutes and the total bill was less than what I paid for the previous muffler at NAPA.

Exhaust systems are something I’ve done in the past…but I really don’t want to do again. Really need a lift…and many times a torch.

For my own exhaust systems I always used stainless steel bolts & nuts with antiseize applied. Even after years under the car, they’d come apart like they were new.

I am a cheapskate and I usually pay someone to do exhaust work. If you don’t have the tools, a lift, and the time . . . it sucks. This is one job I will pay someone to do. Go to an independent shop, they are usually pretty reasonable. I’ve never done a chain muffler shop so I can’t comment. Rocketman

After some youthful DIY on exhaust systems (once on the way to Canada from WI, using a Coke can and two hose clamps) I have been nothing but happy and considered it money (and a very reasonable amount of money) well spent to turn over exhaust work to a local exhaust specialty shop.

I guess I’m with the others. If you have to ask, you should have someone else do it. I’ve done it a few times but I just cut the bolts with an angle grinder and use new bolts, but there are some flanges that are questionable if they can be serviced or not without a closer look. Its a dirty job in close quarters so best to let someone else handle it.

Wow this was unanimous, pretty surprised. Ya I was undecided if I should mess with it, but if those studs and nuts were in better condition I’d would of gave it a shot and if the front connection was nut and bolt I’d probably cut it off and attempt to replace it and hope for the best with other things.
Being underneath the car it’s not to bad for me, I got decent room to slide around, on the ramp I use if everything ran fine but if got into problems then it would be a bit of a nightmare and not much room for power tools under there.
And on top of it being the flex pipe only that has the leak it’s not insanely expensive to bring to a shop. So I guess I’ll bring it there and probably save me a headache and stress.
But it does sound like you guys don’t mess with exhaust repairs even if it’s in better condition than mine. So that’s going to make me not want to touch mine. Thx for all the comments