exhaust leaks fixable?

I checked my exhaust for leaks with an air blower backflow and spraying soapy water everywhere. The flanges against the engine are good, as far as I could access from the top anyway. 3 flange junctions after that are leaking air as indicated by my soapy bubbles:

1. Top of flange junction closest to the engine on passenger side
2. Side of next flange junction exiting engine bay
3. Top of flange junction just downstream of cat. (the one just upstream of cat is fine)

No cracks visible. All downstream of that is good.

Does it look like a fairly easy DIY job with this kind of putty?
https://www.permatex.com/products/s...haust-repair/permatex-muffler-tailpipe-putty/

The flanges are pretty rough with surface corrosion, so I don't know how much I'll be able to clean up the surface, and don't even think about removing those corroded nuts to try to remove anything to clean it up. The exhaust pipes look fine.

See bubbles below.

 

Try new gaskets first. They're cheap.

 

The nuts and bolts by the cat are too corroded for me. The other ones maybe. But the diagrams don't really list all the nuts and bolts, and they have a few listed that are discontinued, and I can't even find the first flange in the diagram. It's right by the manifold on the passenger side but isn't shown.

https://parts.toyota.com/a/Toyota_1...-2WD/_50016_6725139/MANIFOLD/675460-1701.html
https://parts.toyota.com/a/69362386__6706979/EXHAUST-PIPE/671450-1702.html

 

Ok, it looks like for the spots in the engine bay these are all nuts and studs on the exhaust flanges and are probably in removable condition. I'll order the gaskets and a ton of nuts. Hopefully I'll be able to remove enough parts without too much trouble to get that section off the studs and not end up having to remove the exhaust manifold itself or something down at the cat where things are corroded. I'll maybe deal with the leak by the cat later on.

I just saw a pic of a broken exhaust stud yesterday in a meme, and I'm not feeling great about that.

 

Heat is a must and if you can and pre soak those badboys in penetrating oil.

I didn't have a cutting torch at the time of my install so a local shop heated up and loosened the bolts for me before I ruined anything on my own.

 

I agree on replacing the gaskets. I had leaks in the passenger side header/crossover connection. I just bought the two gaskets for those (one per side), and the third that connects the crossover pipe into the exhaust.

My truck was parked in the garage for a few weeks while I was doing a rear axle rebuild, and front end refresh, so I was able to soak the exhaust nuts in pb blaster for a few days in a row without starting the truck (and burning the pb blaster off). I very carefully went out breaking the nuts free. I have a 1" body lift (cause I used to run 285s, and didn't want to hammer the body work) which made accessing the nuts through the fenders more possible. I'll tell ya this- it still sucks. There isn't an easy way to get at those nuts. But a lot of patience later, the job was complete. Installed the new gaskets, with new nuts. I did not install new studs, as I didn't mangle any of them, and they seemed fine. I did have some on hand though.

If I were to do that again, I would get a right angle impact adaptor and a buddy (one person to position the end of the right angle, and press it onto the nut, and the other to run the impact).

I was just under there the other day and noticed that the flange between the last cat and the rest of the exhaust is looking pretty toasted, so I gotta get that gasket and see what I can do.

 

Ya, multiple applications of penetrating oil over a couple nights, and go by an impact gun. I still have scars near my knuckles from trying to take these bolts off without one.

 

I have the impact, and the right angle adaptor.. I was just apprehensive to use it, and you really need a second person to get full pressure on socket.

 

Are you guys saying even the ones in the engine bay should be terrible to remove? I actually tested two nuts at the manifold and I was able to break them free dry. But I'm not sure offhand about being able to get an angle with the breaker bar on all of them. I'm not so much concerned with the leak by the cat (number 3 in the diagram below) where the nuts are badly corroded.

But again I don't know how much exhaust I'm going to have to remove just to remove one or two pieces, with all the studs I have to get them free of. Any experience with taking pieces of the exhaust off on this? I'm hesitating and might have a shop do the entire set of exhaust gaskets if I can't get all the nuts off that I need to for leaks 1 and 2.

Leaks 1, 2 and 3 below. The part in the bottom right of the first pic is the exhaust crossover. Its position in the diagram threw me off at first because it connects to both left and right manifolds.

 

I've tried that exhaust putty before, it didn't hold up at all. Better off trying the gaskets, and if that doesn't work a new exhaust.

 

Double check your exhaust.

There is a version where location 2 has a single gasket. The two crossover pipes converge into a single pipe at the flange.

Location 1 has a counterpart on the drivers side as well. You'll need to undo that flange / connection to be able to move the exhaust enough to get the passenger side gasket out.

Yes, location 1 bolts are the knuckle busters. If you're able to get those out easily, then go buy a lotto ticket (and share the winnings).

 

Good to know. Did you give it 24 hours to cure? One guy helped it along with a heat gun instead of idling the engine the way it recommends, to prevent it from getting blown out while being heat cured.

 

I’d definitely replace the hardware and use oem gaskets. Get ready to drill/extract broken studs.

 

I just finished my exhaust from manifold to tip on my 95.5. Best purchase was a map gas blowtorch to use on each bolt/nut. They looked original to the truck, so 18 years old? Lots of crumbly rust. I replaced most of it with cheap eBay pipes, a muffler, manifold and cat. I had to cut some of the pipes in the exhaust to make everything fit.

The only issue that plagued me was the exhaust manifold kept leaking (even the new one), so I ditched it and sprung for a more expensive manifold. I probably should’ve tried just the gaskets and hardware first, but I’d like this thing to last for awhile so I went for a total re-do.

 

I used a side grinder on those cat bolts when I replaced my cat. Went back with bolts nuts and washers, no issues about 5 years in.

 

I let it cure 24 hours, and it was down by the mufflers (74 Chevelle), but it blew out almost immediately. Better to just fix the problem right off the bat.