Exhaust System Replacement

I have a 2005 Camry. About 200k miles.

My exhaust is leaking pretty badly around the flex pipe connection. Using a shop vac, and blowing air into the exhaust, you can feel it coming out of the flex pipe area real good. It’s also leaking slightly around the flange connections.

I plan on replacing everything past the exhaust manifold, because the amount of money I would spend having an exhaust shop replace just the flex pipe area, I could just replace the whole pipe.

My nuts and bolts clamping the flanges together (except for the exhaust manifold to catalytic converter pipe) are rusted very badly. I don’t think they can be reused. Is there a type of high temp grease or something that I can place on my new bolts and nuts to prevent them from rusting this badly again after I clamp them down?

I believe I’m supposed to use a copper based anti seize, when I remove the oxygen sensor from the old pipe and install it in the new one. I have regular Permatex copper based anti-seize. It doesn’t mention that it’s for high heat applications or anything, but it will be ok in this application?

Is there a type of high heat RTV or something like that, that I can place on the outside of the flange to ensure I got a good seal? I’m going to use the gaskets that come with the parts in-between the mating surfaces, but I’m wondering for outside of the mating surfaces, if there was some kind of high heat RTV or silicone that I could also use?

I wouldn’t worry about trying to protect or seal anything. Use good parts, and you may get 200,000 miles out of the new exhaust.

I’ve replaced exhaust systems, (entire/partial) in vehicles for over 50 years, and have never used any type of anti-seize on the hardware.

There’s two ways to remove hardware on exhaust systems.

Either with hand tools or impact tools.

And when neither of those work, then you use the blue wrench.




Assume those rusty bolts will break. Be happy if they do, otherwise you’ll need the blue wrench… you likely will have to knock studs out after they break.

The only way to prevent them rusting again is to use stainless steel fasteners that don’t rust.

Your anti seize is fine. Yes there is exhaust rated RTV but you should not need it.

Don’t put stainless steel hardware thru heating/cooling cycles over a long period of time.

If you do, you’ll need the blue wrench anyway.


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True… But they won’t rust!

Bolts are cheap. You just cut them off and use new. Not having a torch, an angle grinder with a cutoff wheel works good. You usually only go through this a couple times and then let a shop do it while you taste their coffee.

Unless you have access to a car lift… I’d suggest taking your car to a local exhaust shop for this replacement.

It may be more expensive on the front end…but they have the tool, knowledge, and access to do this job probably better than you can.

Plus you can sit and drink their “free” coffee.


I agree with ledhed 75. I like to do just about everything on my cars, but by the time I hit 40 I was happy to turn over exhaust work to the pros and gladly pay the (usually very reasonable) bill.

It helps to have a good local muffler shop, which I have found and continue to patronize when needed. They have helped me out with a few fast and cheap repairs as well as more extensive work when it was needed.


Cat back with Rez and single muff will be $600+. Maybe more. $129 systems are long gone.

I had a 2003 Camry with the 4 cylinder. Not long after I got it, I bottomed out on this gravel road and found out later, it damaged the flex section. It took a year or two to fail enough to be noticeable. I bought a replacement flex section but just couldn’t find the time to work on it. So I took it into a local Meineke. The flex normally comes as part of a very expensive section. They had developed a fix section specifically for this and it was a fraction of the cost. Took very little time for them to cut out the bad section and weld in the new. It ran with that for another 12 years before I got rid of the car. Something to consider…

About my 40th birthday I was welding custom exhaust systems from a box of straights and bends!

Really helps build abdominals getting up and down fitting cuts and straights. :crazy_face:

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Just curious, what’s on the inside of that flex-pipe section? The outside appears to be tightly braided wire, sort of like coaxial cable. But what’s on the inside that prevents the exhaust gas from leaking? Or is it just the visible braided wire, nothing on the inside, and the braids are tight enough when new that it doesn’t leak? That section gets flexed at a pretty noticeable angle when I have to jack up the Corolla’s engine to replace the water pump or timing belt, so curious how that part is constructed. And what’s a good way to check if it is leaking? Brush it w/ soapy water?

You start the car and quickly get underneath. Listen for the spot that the loudest sound is coming from.
Gently place your hand near (not on!) that area and if you feel “a breeze”, you have found your leak.
I have become very adapt a hearing a change in engine noise on my 2007 Tuscan. I can hear a pinhole in the exhaust from the driver’s seat.
Everybody else in this forum is correct.
When the exhaust starts acting up, bite the bullet and replace everything at a good muffler shop.
Don’t ask how I know this.
I currently have a “Frankenstein” exhaust system made up of various patches and welded pipes.
It’s holding for now but this is a spare car for us so it doesn’t go far.

I also don’t understand, I thought you can’t weld onto rust. I know they make universal flex pipes, you can cut out the old section and replace just that section, but would you weld the replacement onto the rust of the exhaust that is old and rusty? Or they would just clamp it down instead? I think I could do that myself no problem.

I think the rest of the exhaust is leaking slightly at the flanges as well. Bolts rusty so badly, don’t think I could get them off with hand tools or an impact, doesn’t look like there’s much left of them, can’t even feel a hex. So I would have to replace the rest of the exhaust with it, don’t have a torch I’m afraid.

@Tester Thanks for the heads up on not using stainless steel. It won’t rust, so what part of it would make it difficult to remove, even with no rust? Also I thought most oxygen sensors come with some kind of anti-seize in their box, or already applied to the threads? That’s why I was asking, because I plan on re-using the old ones.

@TwinTurbo why did you eventually get rid of your 2003 camry, just wondering?

@George_San_Jose1 used a shop vac and blew air into the muffler, put my hands under the flex pipe section and could feel the breeze real good. On this car, it’s an accordion looking pipe under the braids it seems.

Found it in this video Toyota Camry, Replace Muffler, Resonator Pipe, Flex Pipe With Catalytic Convert, FnF576 - YouTube
I also jacked up my engine a bit for tensioner, wondering if that placed unnecessary strain on the flex pipe section, might have been wise for me to unbolt that section from the exhaust manifold.

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Here we go again . John Smith taking something and making an ordeal out of it . A muffler shop can solve this in a short while for not much more money than doing it yourself.

Had a bender guy replace everything and weld split catalytic converter for less than I could buy parts, with lifetime warranty. 7 years later the muffler went and cost me $2.30 for a muffler clamp. Shop around!

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There comes a time where it may be too rusty to save. We can’t see your parts. But unless it is falling off, there is usually areas that are structurally sound that can be cleaned up and welded onto. An exhaust shop can usually tell from a brief look over.

Nothing wrong with an entire replacement, especially if DIY with minimal exhaust work type tools and you have the financial means to buy all the parts new. But at almost 20 years old, you have to weigh the cost against the expected years remaining.

I always hated that exhaust setup as it came from the factory. I saw no reason they hang down so low. Look at Camry’s on the road and you’ll see how low below the floor pan most of the tubing is fabricated to hang. You can see it driving behind them.

The Camry was one of the best cars I have owned from a repair standpoint. Nothing more than routine maintenance. Even the OEM battery lasted more than 11 years. It sat outside its entire life and toward the end, hardly got used. Mice got into the ducts and fouled it up.

None of this is Rocket Surgery.

Fit a cut-off disk on an angle grinder, grab the saws-all with a metal cutting blade and cut the old exhaust off the car. Cut the front bolts with the disk, saw through the pipe at the rear flange. Don’t even try to un-screw the bolts. It does NOT need to be pretty! WD-40 on the rubbers so you can remove the hangers. Should take 15 minutes tops.

Install the new system loosely. Tighten when it is all is in place. Should take 1/2 an hour. Use whatever bolts you have around that fit. They won’t have to survive another 15 years because the car will be dead and gone before that.

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Mr. Mustang , well written post and way too logical for J. Smith . He will spend 2 days trying to find something to use insteat of WD40 . 2 more days to research torque rating for the non matching nut and bolt sets he has.

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