[Splieslife]

Hello,

I’m a moderately skilled mechanic confident in my abilities.

I have a 95 Camry 2.2 with an exhaust leak between the first cat and exhaust flange that leads below to the flex pipe. This is also near the point where the supports bars from the engine block connect to the exhaust. I have determined that a leak is present with soapy water. I had previously experienced strong exhaust smell in the cab in stop and go traffic.

I have pinpointed the likely cause as the supports brackets both missing one stud/nut each (meaning they aren’t doing their job.) This motor broke a motor mount previous to my ownership (it’s been in the family) which could’ve also loosened up these studs.

Also the first support bracket between the flex pipe and second cat which bolts into the frame was also missing it’s two bolts which certainly further strained the flange.

I would like input on how to best address this leak. Can this flange gasket be changed just by unbolting it from the first cat and swinging it down (relying on the flex pipes flexibility). It’s my understanding that exhaust manifold bolts tend to be brittle and I’d like to avoid breakages if I don’t need to remove the manifold.

I tested the exhaust manifold and seal between the manifold and cat; I did not see any bubbles from the soap. Would it be best to just leave these alone if no leak is evident?

Ill be replacing the bolts that hold the studs and nuts that hold the support bracket with OEM Toyota studs/nuts (I’m worried that just replacing the missing ones may place strain on the older, likely brittle studs that are in place currently). I’m also going to get that support bracket remounted to the frame with oem hardware if possible/ available.

I’m just looking for advice/ thoughts so I can avoid creating problems for myself. I live in California and the car is low miles (165k) so corrosion isn’t excessive but things are definitely rusty.

Thank you for your input!

 

[1990Toyota]

he first cat and exhaust flange that leads below to the flex pipe

Im not sure what you mean first cat??? Unless you mean the exhaust manifold and the flex pipe? Its been a while but I believe the cat on these is further down.



Can this flange gasket be changed just by unbolting it from the first cat and swinging it down (relying on the flex pipes flexibility).

This is how its done... IF you can get those bolts off they can be a bear and may require heat / a torch. Once they are off you can just slide thwe pipe out of the way, clean up the area / remove the gasket and put a new one in

 

[Splieslife]

Hey there,

I believe the 95 2.2 has two cats. One in between the exhaust manifold and first flange (it’s also between the first and second o2 sensors). The second cat is after the flex pipe.

Copy on just removing the flange from the lower exhaust. I think I’ll avoid messing with the exhaust manifold, I do not want to extract any broken bolts.

I was planning on just using my Makita 1/2 impact with something like 450ft/lbs of loosening torque from underneath the car. Can anyone think of any reason a breaker bar would be better? I’ve always understood impact to be safer to avoid bolt breakage.

 

[Splieslife]

Oh and btw, does anyone know torque specs for the flange bolts and the studs and nuts on the support bars?

 

[1990Toyota]

Hey there,

I believe the 95 2.2 has two cats. One in between the exhaust manifold and first flange (it’s also between the first and second o2 sensors). The second cat is after the flex pipe.

Copy on just removing the flange from the lower exhaust. I think I’ll avoid messing with the exhaust manifold, I do not want to extract any broken bolts.

I was planning on just using my Makita 1/2 impact with something like 450ft/lbs of loosening torque from underneath the car. Can anyone think of any reason a breaker bar would be better? I’ve always understood impact to be safer to avoid bolt breakage.

they say the impact vibration on it / gets the bolt off quicker so it avoids stress on it.... but I've personally had better luck with a breaker bar, heat and luuubbbeee juice.

 

[1990Toyota]

Oh and btw, does anyone know torque specs for the flange bolts and the studs and nuts on the support bars?

.02


i generally do a tighten till tight / feel / no leaks on exhaust. Not excessively tight so you squash the gasket.... but...kinda like an oil pan plug

 

[tmauldin]

Try 20 ft lb on the flex pipe to first cat.
Impact wrench didn't work for me in that area, had to use 18 inch breaker with 24 inch cheater pipe to loosen

 

[Splieslife]

Hello all,

Just an update, the impact gun did the trick for me instantly. I immediately realized that the real cause of my exhaust leak was a missing nut on one of the three studs on the flange. The one with the missing nut had thread damage. I was able to clean up the threads with a thread chaser.
However once I got a nut on the offending stud I discovered that it was slightly bent. I threw some washers under the nut so it would seat (the bend was slight and near the base) and managed to get everything back together.

Everything ran smooth for a few days until the sound and smell came back. I discovered one of the other nuts had fallen off (not the one on the bent stud).

I think the bent stud might be compromising the whole fastener arrangement.

I’m going to pull the cat off and replace the bent stud, possibly all of them while I’m there. Kind of an annoying job but I hate smelling exhaust. I’ll also replace the cat gasket while I’m there. Taking the cat off seems mellow except for the bolt/nut in the back, closest to the engine.

 

[Splieslife]

Hello,

So question concerning the cat (the upper one which attaches to the exhaust manifold and is above the flange). Is there any reason I can’t find any information about removing just this part? All the videos I can find show removal of the manifold and cat as one piece.
In my case, my exhaust manifold is a-ok and I’d prefer to leave it alone. The only thing I can see as a hindrance to the removal of the cat is the nut or bolt that’s in the back, closest to the engine. I had to pause today to make an appointment before I could tackle that, but it looks like I could get a wrench on it if I remove my oil filter and then give the bolt/nut some taps with a hammer.
Again, I want to remove the cat so I can swap out a bent stud that’s causing an exhaust leak at the flange. It may be possible to swap the stud while the cat is on the car but the angle from which I’d have to work on it from under the car is quite difficult.

Does anyone have any insight? I guess if I can’t remove that final bolt/ nut tomorrow I’ll understand why nobody takes the cat off. It seems doable to me though

 

[1990Toyota]

Some people might find it easier just to remove the thing as a whole unit. If you can reach it, I say try.

 

[93celicaconv]

I believe the attached diagrams are for your 1995 Camry 5S-FE Exhaust Manifold & Exhaust Pipe. The 3-stud flange attachment is between the end of the exhaust manifold and the start of the exhaust pipe. I don't see an "upper" CAT on the diagram. You are saying yours has an upper CAT? I'm wondering if a previous owner had a problem and the solution was taking an exhaust manifold and upper CAT from an older Camry and put it on to solve an earlier problem?

 

[Splieslife]

Hello,

I can’t find the diagram that the dealership printed for me, but I have the same thing showing the presence of a factory cat in between the exhaust manifold and the first flange.
My Camry is a 95 2.2 California model (so maybe it’s because of California). The gasket I received from the dealership for the cat/ manifold interface is #25576-74030.
My situation is definitely factory. A lower cat wouldn’t bolt on like my upper cat does. It also says ‘Toyota’ very clearly on the cat.
Cheers

 

[1990Toyota]

I was thinking it could be cali emissions.


A bent stud is kinda rare though, usually they break right off....seems like the last person tightened the heck out of those.

 

[93celicaconv]

I can’t find the diagram that the dealership printed for me, but I have the same thing showing the presence of a factory cat in between the exhaust manifold and the first flange.
My Camry is a 95 2.2 California model (so maybe it’s because of California). The gasket I received from the dealership for the cat/ manifold interface is #25576-74030.
My situation is definitely factory. A lower cat wouldn’t bolt on like my upper cat does. It also says ‘Toyota’ very clearly on the cat.

What is your VIN? That would help us who are/were trying to help you. This is the first time in this thread that California emissions came up. But we can help with correct diagrams if you provide your VIN.

Otherwise, lacking a VIN, maybe this diagram is for your vehicle?

 

[Splieslife]

 

[Splieslife]

Hello,

Please see above;

1. Void from the cat removal
2. Two studs, top one is bent, you can’t hardly tell from the photo, this bend is maybe a degree or two but it’s there. Damage to the threads is what’s left from the initial damage (cause unknown) and my thread repair.
3. Cat on the bench, these studs are tough to remove even with Pb blaster and nice 7” knipex. I haven’t messed with heat yet.
4. Cat in place on car. Removal requires;
-Remove three bolts and two nut/studs combinations from the upper flange (all were 12mm)
-may not be necessary but I removed the front heat shield, takes (x4) 10mm bolts
-Disconnect your support brackets (these go from the engine to the cat just above the flange, there are two, one on the driver and one on the passenger side) they were 14mm head nut/stud combos. I’m missing the driver side/engine side stud/nut combo, (it appears to be a larger size stud, these others were m8x1.25 (based on memory, not 100% sure on that) I think this stud may be M10).
-remove the three m8x1.25 nut/studs (my heads were 14mm) that hold the flange together from beneath the car. I hit these with Pb blaster and my impact gun made short work the next day.
-you’ll need a metal gasket for the cat/ manifold matting surface and for the cat/flange matting surface

 

[1990Toyota]

so lucky they came off!!!


you can try to see if you can get them from toyota... but you can probably jst go to NAPA and have them match them for you

 

[Splieslife]

Hey there,

I managed to score some studs from Toyota. Hopefully this gets me sorted out. I did notice that the bottom mesh of the cat was pretty badly melted and deformed. Hopefully that continues to run!

cheers

 

[93celicaconv]

And the Toyota part numbers are in the post with the second set of diagrams I previously posted.

 

[93celicaconv]

Hey there,

I managed to score some studs from Toyota. Hopefully this gets me sorted out. I did notice that the bottom mesh of the cat was pretty badly melted and deformed. Hopefully that continues to run!

cheers

Maybe post a picture of that deformed mesh? You don't want to cause a flow block (exhaust pressure increase in the manifold) with a restrictive cat.