Y-pipe install

[Adoniram]

With the lack of ability to simulate the O2 sensors on the '13+ headers, I'm ditching the header upgrade and just going with the URD y-pipe. That said, I'd like to ask people here how difficult of an install this is. It would seem rather straight-forward, like I could just crawl under the vehicle and do this in an hour or so...

But then there's always the possibility that there's loads of head shields, bolts, and other things that need to come off first. Who has done this, and what was your experience?

If it's simple, I'll order it pronto before my move to Colorado. If it's a lengthy job, I'll just wait until I get there and use my buddies lift. Thanks!

 

[empty403]

With the lack of ability to simulate the O2 sensors on the '13+ headers, I'm ditching the header upgrade and just going with the URD y-pipe. That said, I'd like to ask people here how difficult of an install this is. It would seem rather straight-forward, like I could just crawl under the vehicle and do this in an hour or so...

But then there's always the possibility that there's loads of head shields, bolts, and other things that need to come off first. Who has done this, and what was your experience?

If it's simple, I'll order it pronto before my move to Colorado. If it's a lengthy job, I'll just wait until I get there and use my buddies lift. Thanks!

Not difficult if you don’t have rusty bolts. Check them and/or start spraying them with Liquid Wrench. The toughest part would be snaking the Y-pipe out because of the size of the catalytic converters. You know you can install the headers and add O2 sensor extensions which will eliminate the CEL. But you’ll have horrible & deadly fumes if you remove all 4 cats.

 

[Adoniram]

Ok I think I'm confused about how many O2 sensors there are...

-It appears there are 2 sensors at the top of the y-pipe (side closest to the engine).
-There are 2 sensors after the stock cats on the headers. This is what causes the trouble on the 13+ units.
-Are there an additional 2 sensors pre-header-cats?

Also, why on Earth are there 2 sensors post-header-cat, and 2 sensors pre-y-pipe-cats? Those seem completely redundant...!

Anyway, if I replace the headers (but not the y-pipe), what would the extender do for me? Would I have to drill extra O2 ports on the stock y-pipe post cats?

 

[empty403]

Ok I think I'm confused about how many O2 sensors there are...

-It appears there are 2 sensors at the top of the y-pipe (side closest to the engine).
-There are 2 sensors after the stock cats on the headers. This is what causes the trouble on the 13+ units.
-Are there an additional 2 sensors pre-header-cats?

Also, why on Earth are there 2 sensors post-header-cat, and 2 sensors pre-y-pipe-cats? Those seem completely redundant...!

Anyway, if I replace the headers (but not the y-pipe), what would the extender do for me? Would I have to drill extra O2 ports on the stock y-pipe post cats?

There’s pre and post O2s for the ECU to calculate fuel mixtures. You’ll need the O2 extensions on the post cat O2 sensors, if you remove the 1st set of cats at the headers. I’m not familiar with the newer V6 headers. Are the Cats welded onto the OEM exhaust manifold or bolted up to them?

 

[Adoniram]

The cats are part of the headers. I was wanting to go with long-tube headers which delete the header cats, but you can't simulate the rear O2 sensors in the 13+ units like you could with earlier units.

I just re-checked some pics of the headers, and there are indeed pre-cat ports (on the headers), and post-header-cat ports (on the y-pipe). There are no ports post-y-pipe-cat.

So total of 4 O2 sensors. I still don't understand what the extender does for you. Where would you hope to place the rear O2 sensors such that you could avoid the CEL? It seems you'd have to drill your own ports post-y-pipe-cat.

All this trouble with the headers is why I wanted to go with the y-pipe instead. I'll be leaving the stock headers (and cats) in place. I'd rather delete the header cats, and replace the y-pipe with high-flow cats, but that's not an option...

 

[wfo9]

As far as the Y pipe goes it is a super easy install. Only Issue I had was the need to drill out the flange holes a bit on the new pipe.

I did not really install it for power gains. the big advantage of it for me was clearance. The crossover hangs down low and forces any type of skid plate to also be low... hurting break-over angle offroad. But there is obviously a little performance gain.

For the headers.. they may include an extension harness for the WB o2 (primary) sensors since they would sit further back. The secondary sensors would be useless and there would be no point in using them as they would simply set a CEL all the time without the cats in place. You would be better off just plugging the holes for them with a plug.

 

[oljedi11950]

Being how mine is an 11' , very easy crawled underneath saw where o2s were & got the 22mm sensor tool wrench took them off & sprayed the crap with Pb blaster came back 1/2 hr & started unbolting ! Took me an hr . Have not f-d with upstream a/f sensors ! Simple 2 on the scale !

 

[AlblineStar808]

as far as the sensors i was told by gadget that i wouldn't have any issues installing my long tube headers and adding my y pipe and hi tuck exhaust. i asked about an 02 simulator and he said it wasnt needed. now im kinda frustrated as ive been going back and forth with him and don't want to run into any issues doing this install

 

[Adoniram]

as far as the sensors i was told by gadget that i wouldn't have any issues installing my long tube headers and adding my y pipe and hi tuck exhaust. i asked about an 02 simulator and he said it wasnt needed. now im kinda frustrated as ive been going back and forth with him and don't want to run into any issues doing this install

What year is your vehicle?

 

[AlblineStar808]

What year is your vehicle?

jus got back word it will now which frustrates me because i wouldn't of ordered the y pipe and exhaust

 

[Adoniram]

Yeah... You should still be OK with the y-pipe and exhaust though. The long tube headers are the only thing that causes a problem. Gadget informed me that the O2 simulator was under development, but there's no ETA.

 

[jstack2]

how does it sound? factory rear exhaust section? contemplating this as well but don't want the drone as its my daily

 

[2016 4Runner SR5]

Curious how this sounds and if there is any actual performance improvement when keeping the OEM exhaust beyond the y pipe.

 

[Adoniram]

Removing the 2 cats in the y-pipe is definitely going to improve the performance a bit. I highly doubt there would be any noticeable sound difference if you keep the stock muffler.

For a reference point, I replaced the headers, up-pipe, and downpipe on my '05 Subaru Legacy GT (turbo 2.5L), and kept the stock cat-back. Zero noise difference from within the cab. However, I was getting a lot more power because 3 OEM cats were replaced with 1 high-flow cat, and the new headers spooled the turbo faster.

Anyway... it's not ideal leaving the final restriction (OEM muffler) in place, but by the time the gases have gotten to the muffler, they've cooled a little and the pressure is down a bit. I'm going to try the y-pipe-only method and see how it goes. If there's an appreciable seat-dyno difference, I'll report it (or mpg difference).

 

[Hadelson]

Removing the 2 cats in the y-pipe is definitely going to improve the performance a bit. I highly doubt there would be any noticeable sound difference if you keep the stock muffler.

For a reference point, I replaced the headers, up-pipe, and downpipe on my '05 Subaru Legacy GT (turbo 2.5L), and kept the stock cat-back. Zero noise difference from within the cab. However, I was getting a lot more power because 3 OEM cats were replaced with 1 high-flow cat, and the new headers spooled the turbo faster.

Anyway... it's not ideal leaving the final restriction (OEM muffler) in place, but by the time the gases have gotten to the muffler, they've cooled a little and the pressure is down a bit. I'm going to try the y-pipe-only method and see how it goes. If there's an appreciable seat-dyno difference, I'll report it (or mpg difference).

Would be interested in hearing what the sound increase is. I went to a URD Cat-System. Little to no noise increase around town. On the road, it is louder without any drone. I would think with the Y-Pipe and eliminating rear Cats would see additional sound.

 

[Judd94]

I have a 17 and have been eyeing this YPipe too. Seems like the O2 sensors are a none issue cause they’re after the 1st set of cats and none after 2nd set. My understanding is the 2 nd set is only for use during startup.

 

[2016 4Runner SR5]

Why not take the stock y-pipe off, gut the cats, and reinstall it? Same concept, may not be bent as pretty, but at least you don't have a pipe right under the tranny pan heat soaking it all day. Free too

 

[wfo9]

Why not take the stock y-pipe off, gut the cats, and reinstall it? Same concept, may not be bent as pretty, but at least you don't have a pipe right under the tranny pan heat soaking it all day. Free too

There is no heat going to the tyranny at all. Plenty of air gap. The stock crossover is restricted/crushed and severely limits clearance. The only downside the URD Y pipe is I'm pretty sure you have to remove it to drop the tyranny pan.

 

[Judd94]

Anybody have any actual pics of the Y Pipe installed? Such as the gap between the tranny and pipe and anything else that people may find important?

 

[Friggin Idiot]

Anybody have any actual pics of the Y Pipe installed? Such as the gap between the tranny and pipe and anything else that people may find important?

I tried to get some of those up in my build thread. See this post for the install. Of note since then I did add some dings to the bottom of the Y-pipe the other day, I might have to consider a tranny skid to help protect it. I did consider some heat wrap around the Y-pipe below the tranny, but decided it would actually do more harm than good. It would hold in water, moisture, and the dreaded salt mixture to the Y-pipe likely causing it to rust pretty quickly. Without the heat wrap there's better air flow between the tranny and Y-pipe, so it should be able to dissipate the heat, although I'm not sure about how that would work with a tranny skid. That is assuming the skid doesn't rattle against the Y-pipe to start with.
In adding the Y-pipe, Mk3 3" Stainless Exhaust, and MAF converter, power, noise, and mpg are all up. The Mk3 is a little louder than I expected, but only when you're under acceleration or load. Cruising it's mostly quiet.