1FZ-FE exhaust - finally

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Hey guys, did a quick search but can't find what I'm looking for. I've been working on the 80 (1997) off and on for about a week. Took the entire exhaust out except for the manifolds. Went back with Magnaflow y-pipe and second cat, cheap but correctly fitting muffler, and now I'm fabing up a new tailpipe. Was going to just grab a Toyota one but had a hard time finding them and $300+ for that part seemed stupid when I have tools, including a welder. So, the hiccup I'm running into is how does one install a tailpipe with that ginormous Toyota flange that mates to the rear of the muffler section? I have the first few pieces tacked up with the flange on and I can barely finagle the thing over the frame from the back. If I finish it, there's not a snowball's chance in hades that I can get it to go in....thoughts? I was thinking of making the section that passes over the frame really short and adding another flange connection. Not what I want but the only way I can figure getting it to fit. Thoughts? And how in the heck does an OEM tailpipe get installed? Mine had been modified to be shorter and I used a sawzall to remove it because I was gonna trash it anyway and I didn't think snaking the new one in was going to be as difficult as it has proved to be.
 
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Top photo you can see where the muffler flange is. Same placement as stock muffler, give or take a little. Second photo you can see the heat shield where the OEM tailpipe ran over the frame. I'm going to follow the same path. I just can't figure out how that long original tailpipe got installed in the first place?
 
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Since Toyota sells the tail pipe as a replacement part,you can be sure that there is a way to get it in. Having the old pipe intact would help to figure it out. You might need to jack it up to create more clearance or temporarily remove a part. It seems like you are piecing together a replacement, so you can just keep on building it in place from front to back. You may have to loosen the hangers or the front connections to get the clearance to weld it all the way around or you could just continue tacking it and then remove it and weld it out.
 
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Any ideas are welcome. I don't relish the thought of yet another flange but I currently can't see a way around it. Kind of aggravating.
The original tailpipe is removable in one piece if you Tetris it correctly.

You need to drop the spare tire and jack it up to drop the rear axle but you do not need to lift the body from the frame.

You remove it from the rear of the truck. You may have to rotate and twist numerous times to get it oriented properly.
 
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Since Toyota sells the tail pipe as a replacement part,you can be sure that there is a way to get it in. Having the old pipe intact would help to figure it out. You might need to jack it up to create more clearance or temporarily remove a part. It seems like you are piecing together a replacement, so you can just keep on building it in place from front to back. You may have to loosen the hangers or the front connections to get the clearance to weld it all the way around or you could just continue tacking it and then remove it and weld it out.
I know that the original can be installed in one piece. Either that or aliens helped Toyota because there's no weld beads on the OEM piece...I just didn't know what the procedure was to install it. I always figured you just weaseld it on in there but there isn't enough space. At least, not with the truck sitting on the rear axle.
 
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The original tailpipe is removable in one piece if you Tetris it correctly.

You need to drop the spare tire and jack it up to drop the rear axle but you do not need to lift the body from the frame.

You remove it from the rear of the truck. You may have to rotate and twist numerous times to get it oriented properly.
Ah, that would make more sense. Although in may case I've opted for a second flange (time constraints, not going to explain now)
 
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Your second cat is in backwards. Check your flow arrow and they should be both horizontal with the Magnaflow.
I believe you, based on other conversations we've had - but I don't see how. I played with that second cat for a few minutes when I was bolting it up. If you flip it around, the flanges don't seem to mate up right but maybe I just wasn't paying enough attention. I guess reversing it would have to work because both flanges are parallel - math, degrees of rotation, all that jazz....sigh. And I may just be losing this fight on all fronts but what flow arrow? I looked for one. Didn't see it..
 
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I believe you, based on other conversations we've had - but I don't see how. I played with that second cat for a few minutes when I was bolting it up. If you flip it around, the flanges don't seem to mate up right but maybe I just wasn't paying enough attention. I guess reversing it would have to work because both flanges are parallel - math, degrees of rotation, all that jazz....sigh. And I may just be losing this fight on all fronts but what flow arrow? I looked for one. Didn't see it..
I'll see if I can find one on mine.
 
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Your second cat is in backwards. Check your flow arrow and they should be both horizontal with the Magnaflow.
Just crawled under the truck again to take a look-see. No flow arrow on that cat as far as I can tell. Also, the flanges are not 90 degrees off from one another so making the body "horizontal" by reversing it would put it at roughly a 20 deg angle instead of actually being horizontal. I'm happy with it as is unless there's some directional magic to catalytic converters (not that I'm aware of but open to input)
 
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There's also a heat shield on the second cat. The only reason I could figure on why the second one has a heat shield and the first (on the y-pipe) does not - is possibly because it is mounted vertically as I have it. When installed that way, the heat shield is on the exterior side of the cat and protects the inside of your rocker panel from undue heat. It already has a factory heat shield above it, so why add one unless you knew the orientation was going to be weird? Just my thought process. Could easily be wrong.
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My buddy has some 3" oval exhaust on his C10, I bet you could find some 2.5 or 2.25 oval exhaust that would slide over the frame. If you have the exhaust already, I read a post earlier that says you need to lift the body off the frame to make things easier.
 
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There's also a heat shield on the second cat. The only reason I could figure on why the second one has a heat shield and the first (on the y-pipe) does not - is possibly because it is mounted vertically as I have it. When installed that way, the heat shield is on the exterior side of the cat and protects the inside of your rocker panel from undue heat. It already has a factory heat shield above it, so why add one unless you knew the orientation was going to be weird? Just my thought process. Could easily be wrong.
View attachment 3074177
Remove the rear cat. Swap it end for end, then turn it 90° and it will be horizontal.
 
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Remove the rear cat. Swap it end for end, then turn it 90° and it will be horizontal.
No, it won't. That's what I was saying earlier. If the flanges were 90 degrees out of alignment, that would work. But they are less than that (or more, depending on which direction you measure) so if I turn it around it won't be horizontal it will be cocked to one side. Not trying to be a jerk, just talking my way through your suggestion. In the grand scheme of things does it matter though? My rock sliders have a skid for both cats and one of the Toyota ones was vertical so it should fit. And still no flow arrow that I can see...
 
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Also, finished welding up the tailpipe. Didn't get a picture before it started raining but the extra flange attachment worked as desired. Allowed me to attach the elbow that travels over the frame, then bolt up the rest of the tailpipe from the rear of the vehicle. Not factory but it was never gonna be. Time will tell if my welding and fitment are satisfactory.
 
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No, it won't. That's what I was saying earlier. If the flanges were 90 degrees out of alignment, that would work. But they are less than that (or more, depending on which direction you measure) so if I turn it around it won't be horizontal it will be cocked to one side. Not trying to be a jerk, just talking my way through your suggestion. In the grand scheme of things does it matter though? My rock sliders have a skid for both cats and one of the Toyota ones was vertical so it should fit. And still no flow arrow that I can see...
No. Look at your picture above.

Take the far end and swing it out to the right until it is all the way around and is pointing toward you.
Then rotate the body from vertical to horizontal and the flanges will align.

Believe me, this works.

I have to explain this kind of stuff to Engineers all the time.
 
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No. Look at your picture above.

Take the far end and swing it out to the right until it is all the way around and is pointing toward you.
Then rotate the body from vertical to horizontal and the flanges will align.

Believe me, this works.

I have to explain this kind of stuff to Engineers all the time.
It will bolt up because the angular displacement is the same in both directions. However, the body of that catalytic converter will not be horizontal with respect to the body of the vehicle. It can't. The flange in the foreground of that photo (the one that would be mating up to the other cat if I turned it around) is not parallel to the horizontal axis of the cat. The rear flange of the first cat is...so if I bolt them together the body of the second cat will be canted. I don't see how that gains me anything.
 

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