1997 FZJ80 exhaust leak -- ouch ($$$$)!

[PolarBear]

Hey guys, my old ’97 FZJ80 (that I purchased new) just developed a loud exhaust leak. It appears to be where the oxygen sensor attaches to the front pipe/headpipe between the exhaust manifold and the forward catalytic converter. It’s all rusted out there. Midas Muffler says that’s all one piece (headpipe and front catalytic converter) and will cost about $1,100 to replace. Any thoughts on alternatives? All things being equal, I’d rather have our excellent local Toyota dealer do the repair, unless it’s going to cost twice as much.

 

[AlaskanLX450]

Magnaflow cat and y-pipe assembly from Amazon, Denso O2 sensors at the same time. Spray the hardware with some rust penetrate now and it should come apart nicely when the parts arrive. I did mine on the ground with the passenger tire off, couple long 3/8 extensions and youre good to go. I suggest getting new down pipe studs and nuts from Toyota and new studs and nuts between the front and rear cat too, unless youre going to get a new rear cat at the same time.

 

[Cass007]

Heads up on the O2 sensors. I can't say abount Denso, but avoid the Bosch. When I had those they caused a CEL until I swapped them for stock sensors.

 

[Fletcher34]

Denso is stock.

 

[Tedward]

I just replaced the y-pipe/down tube and 1st cat with Magnaflow. Also, I got the Magnaflow 2nd cat. It's all direct fit. No mus no fuss. I'm not nearly the first to do so. The Toyota piece is just too expensive to justify.

 

[051009]

I just replaced the y-pipe/down tube and 1st cat with Magnaflow. Also, I got the Magnaflow 2nd cat. It's all direct fit. No mus no fuss. I'm not nearly the first to do so. The Toyota piece is just too expensive to justify.

Apologies to revive an old thread but did you have issues with getting the 2nd cat to mate up to the rear exhaust pipe? There is a lip on the rear exhaust pipe and the pipe diameter is too large and the Magnaflow 2nd cat's pipe is too small and the exhaust won't fit into it...

 

[Tedward]

No I had no problems. From what I've read on mud Bosal may now be making/supplying these magnaflow exhaust parts. The stuff I used was for sure Magnaflow stuff and the fit is right on.

 

[wxm]

Please keep us updated about the Magnaflow 2nd cat. I replaced the y-pipe and 1 cat last year. May have to do the 2nd soon.

 

[051009]

From my other thread it looks like others just cut the lip off the stock piping and used 2 gaskets...

I don't understand why a "bolt on" product would need something like this, I'm leaning towards returning it and looking for another solution.

wxm - did replacing just cat 1 make your P0420 issue go away (assuming that was your issue as well)? I'm diagnosing the same issue but trying to do just cat 2 since it's easier to reach.

 

[PolarRunner]

Speaking of the magnaflow, it’s selling on amazon now for $511. When I initially looked at it early last year, it was under $300. Eff that noise, gonna have to diy it. To the welder.

 

[051009]

Front including Y pipe or rear single cat? Front cat including Y pipe is up to $642 now and the rear single is $437 which is why I was hoping just replacing the rear single one would fix my P0420 issue. For these prices you'd think they could at least get the fitment right...

Links for reference

Front (with Y pipe):
Front with Y pipe
Rear:
Rear cat

 

[jatree]

I've got a P0402 issue I haven't looked into yet but believe I at least have a leak between the two cats. I was looking at the Magnaflow stuff months ago but was also disappointed by the huge price increase while some people were claiming quality had gone down. Is there a reason you're looking at replacing your y-pipe? I know some people have gone to a single Cat system which is another thing I may consider.

 

[051009]

I've got a P0402 issue I haven't looked into yet but believe I at least have a leak between the two cats. I was looking at the Magnaflow stuff months ago but was also disappointed by the huge price increase while some people were claiming quality had gone down. Is there a reason you're looking at replacing your y-pipe? I know some people have gone to a single Cat system which is another thing I may consider.

Only reason is the front cat/y pipe are all the same age as the rear one and I'd like to deal with it once and be done with it. If I can get a reasonable idea that just the rear cat alone will fix the issue I may be more inclined to just use the cat as is but it's seriously such a pain that a "direct fit" product like this would require modification to work. I really hate making permanent changes to the OEM stuff.

 

[PolarRunner]

Y pipe from the manifolds. 23120. Amazon shows price is currently $511.11.

Edit: Seems a lot of people have gotten a bosal unit in place of a Magnaflow, which doesn't have as good of a fit.

 

[051009]

Y pipe from the manifolds. 23120. Amazon shows price is currently $511.11.

Edit: Seems a lot of people have gotten a bosal unit in place of a Magnaflow, which doesn't have as good of a fit.

Oh gotcha, right this is the non-CARB version. Not going to fly here in CA

 

[BILT4ME]

Do you have the CAT oriented the correct direction for flow? It it possible that the opposite end is a different dimension?

I just realized that I was mating a new cat to a new Bosal Muffler Assembly. Mine may have been a different size, but either way, it's worth a look. The cats are directional.

 

[051009]

Do you have the CAT oriented the correct direction for flow? It it possible that the opposite end is a different dimension?

I just realized that I was mating a new cat to a new Bosal Muffler Assembly. Mine may have been a different size, but either way, it's worth a look. The cats are directional.

Definitely tried that, the piping is identical on both ends. The flanges are also identical on both ends, it leads me to believe this cat is not directional although one side is labeled "TOP" which when oriented that way makes the cat have more clearance with the ground.

The piping diameter is about 2.3" and needs to be about 2.5" to slide over the lip.

 

[051009]

Just in case anyone cares... I called Magnaflow technical support and from their engineering the inner diameter of the piping *should* be 2.5". I measured and remeasured what I have in front of me and the inner diameter of the piping is at most 2.3".

I'm not sure if this one is just built wrong but I'm returning it and ordering another.

 

[jatree]

Just in case anyone cares... I called Magnaflow technical support and from their engineering the inner diameter of the piping *should* be 2.5". I measured and remeasured what I have in front of me and the inner diameter of the piping is at most 2.3".

I'm not sure if this one is just built wrong but I'm returning it and ordering another.

Stinks about the delay but hope they make it right and send you a correct part.

 

[Sandy Cruiser]

Apologies to revive an old thread but did you have issues with getting the 2nd cat to mate up to the rear exhaust pipe? There is a lip on the rear exhaust pipe and the pipe diameter is too large and the Magnaflow 2nd cat's pipe is too small and the exhaust won't fit into it...

The one I got was the same way. Sorry but I didn't take photos of that stage of the project so I cant show you. My experience is "bolt on" anything exhaust usually needs some modification.

This is back yard red neck advice but I cut mine down with a reciprocating saw flush with the flange surface with a lip to hold the gasket. (not cut down to the gasket mating surface.) If you're not comfortable with that because its easy to mess up take it to someone that knows how to do this stuff. Though they're probably just going to cut it down too. Or weld a new flange on witch would be the best way because it would get everything lined up straight.